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Fridman, A.; Lin, A.; Miller, V.; Bekeschus, S.; Wende, K.; Weltmann, K.-D. |
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Title |
The plasma treatment unit : an attempt to standardize cold plasma treatment for defined biological effects |
Type |
A1 Journal article |
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Year |
2018 |
Publication |
Plasma medicine |
Abbreviated Journal |
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Volume |
8 |
Issue |
2 |
Pages |
195-201 |
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Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Abstract |
Plasma bioscience and medicine are both rapidly growing fields. Their aim is to utilize cold physical plasmas for desired biological outcomes in medicine, biotechnology, agriculture, and general hygienic purposes. Great success has been achieved in many applications with individually designed plasma sources and plasma parameters. Although lab and application-specific tuning of plasmas is a great advantage of this technology, standardized units to define plasma treatments are required to facilitate comparison of the effects found by different researchers who do not use the same plasma sources. By drawing conclusions from over a century of plasma biomedical research, we propose that all researchers adopt the use of a standardized value, the plasma treatment unit (PTU), to describe the biological effects of different cold plasma sources and treatment regimens. It quantifies a key plasma effector in biological systems as an indicator and may provide the foundation for an analogous and clinically relevant unit in the future. |
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2018-06-13 |
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Most recent IF: NA |
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Call Number |
UA @ lucian @ c:irua:155652 |
Serial |
5123 |
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Author |
Ranieri, P.; Shrivastav, R.; Wang, M.; Lin, A.; Fridman, G.; Fridman, A.A.; Han, L.-H.; Miller, V. |
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Title |
Nanosecond-pulsed dielectric barrier dischargeinduced antitumor effects propagate through depth of tissue via intracellular signaling |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
Plasma medicine |
Abbreviated Journal |
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Volume |
7 |
Issue |
3 |
Pages |
283-297 |
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Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Abstract |
Studies using xenograft mouse models have shown that plasma applied to the skin overlying tumors results in tumor shrinkage. Plasma is considered a nonpenetrating treatment; however, these studies demonstrate plasma effects that occur beyond the postulated depth of physical penetration of plasma components. The present study examines the propagation of plasma effects through a tissue model using three-dimensional, cell-laden extracellular matrices (ECMs). These ECMs are used as barriers against direct plasma penetration. By placing them onto a monolayer of target cancer cells to create an in-vitro analog to in-vivo studies, we distinguished between cellular effects from direct plasma exposure and cellular effects due to cell-to-cell signaling stimulated by plasma. We show that nanosecond-pulsed dielectric barrier discharge plasma treatment applied atop an acellular barrier impedes the externalization of calreticulin (CRT) in the target cells. In contrast, when a barrier is populated with cells, CRT externalization is restored. Thus, we demonstrate that plasma components stimulate signaling among cells embedded in the barrier to transfer plasma effects to the target cells. |
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2017-09-01 |
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no |
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Call Number |
UA @ admin @ c:irua:155658 |
Serial |
8293 |
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Author |
Lin, A.; Truong, B.; Fridman, G.; Friedman, A.A.; Miller, V. |
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Title |
Immune cells enhance selectivity of nanosecond-pulsed DBD plasma against tumor cells |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
Plasma medicine |
Abbreviated Journal |
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Volume |
7 |
Issue |
1 |
Pages |
85-96 |
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Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Abstract |
Cancer immunotherapy is a promising strategy that engages the patient's immune system to kill cancer cells selectively while sparing normal tissue. Treatment of macrophages with a nanosecond-pulsed dielectric barrier discharge directly enhanced their cytotoxic activity against tumor cells but not normal cells. These results underscore the clinical potential of plasma for cancer immunotherapy. |
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Publication Date |
2017-08-15 |
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UA library record |
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no |
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Call Number |
UA @ admin @ c:irua:155657 |
Serial |
8058 |
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Author |
Truong, B.; Siegert, K.; Lin, A.; Miller, V.; Krebs, F.C. |
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Title |
Apical application of nanosecond-pulsed dielectric barrier discharge plasma causes the basolateral release of adenosine triphosphate as a damage-associated molecular pattern from polarized HaCaT cells |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
Plasma medicine |
Abbreviated Journal |
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Volume |
7 |
Issue |
2 |
Pages |
117-131 |
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Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Abstract |
Promising biomedical uses for nonthermal plasma (NTP) in the fields of regenerative medicine, cancer therapy, and vaccine delivery involve the noninvasive application of uniform nonequilibrium plasma (including dielectric barrier discharge plasma) to living skin. Whereas most investigations have focused on achieving desired therapeutic outcomes, fewer studies have examined the mechanisms and pathways by which epithelial cells respond to NTP exposure. Using a transwell apical-basolateral-chambered system to culture the human keratinocyte HaCaT cell line, in vitro experiments were performed to demonstrate the effects of nanosecond-pulsed dielectric barrier discharge (nsDBD) plasma on polarized epithelial cell viability, monolayer permeability, intracellular oxidative stress, and the release of adenosine triphosphate (ATP). Application of nsDBD plasma at 60 Hz or below had minimal or no effect on HaCaT monolayer viability or permeability. nsDBD plasma exposure did, however, result in frequency-dependent reductions in intracellular glutathione (indicating direct induction of oxidative stress by nsDBD plasma) and increased extracellular ATP concentrations in the ba-solateral (subepithelial) media, which are indicators of cellular stress and an NTP-induced inflammatory response. These studies provide new insights into nsDBD plasma-induced inflammation and local innate immune responses initiated by polarized epithelial tissues. |
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Publication Date |
2017-02-24 |
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no |
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Call Number |
UA @ admin @ c:irua:155656 |
Serial |
7465 |
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Author |
Tsirlin, A.A.; Shpanchenko, R.V.; Antipov, E.V.; Bougerol, C.; Hadermann, J.; Van Tendeloo, G.; Schnelle, W.; Rosner, H. |
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Title |
Spin ladder compound Pb0.55Cd0.45V2O5: synthesis and investigation |
Type |
A1 Journal article |
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Year |
2007 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
76 |
Issue |
10 |
Pages |
104429,1-7 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Place of Publication |
Lancaster, Pa |
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000249786300074 |
Publication Date |
2007-09-25 |
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ISSN |
1098-0121;1550-235X; |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.836 |
Times cited |
1 |
Open Access |
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Notes |
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Approved |
Most recent IF: 3.836; 2007 IF: 3.172 |
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Call Number |
UA @ lucian @ c:irua:65594 |
Serial |
3091 |
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Author |
Lebedev, O.I.; Van Tendeloo, G.; Attfield, J.P.; McLaughlin, A.C. |
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Title |
Defect structure of ferromagnetic superconducting RuSr2GdCu2O8 |
Type |
A1 Journal article |
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Year |
2006 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
73 |
Issue |
22 |
Pages |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
The structure and defect structure of superconducting ferromagnetic bulk RuSr2GdCu2O8 has been investigated using high-resolution transmission electron microscopy and high-resolution scanning transmission microscopy. Two distinct, but closely related structures, due to ordering of rotated RuO6 octahedra and due to Cu substitution in the Ru-O layer, have been revealed. The structure of Ru1-xSr2GdCu2+xO8-delta can be described as a periodic alteration along the c axis of CuO4 planes and RuO6 octahedra. The unit-cell parameters of this phase are root 2a(p) x root 2a(p) x 2c. The possible influence of this phase and defect structure on the sensitivity of the superconductivity and magnetic properties is discussed. Local defects such as 90 S domain boundaries, (130) antiphase boundaries, and the associated dislocations are analyzed. |
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Place of Publication |
Lancaster, Pa |
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Wos |
000238696300115 |
Publication Date |
2006-06-26 |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1098-0121;1550-235X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.836 |
Times cited |
11 |
Open Access |
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Notes |
Iap V-I |
Approved |
Most recent IF: 3.836; 2006 IF: 3.107 |
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Call Number |
UA @ lucian @ c:irua:59707 |
Serial |
619 |
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Permanent link to this record |
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Author |
Tan, H.; Lebedev, O.I.; McLaughlin, A.C.; Van Tendeloo, G. |
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Title |
The superstructure and superconductivity of Ru1222 based RuSr2Gd2-x-yYyCexCu2O10-\delta compounds |
Type |
A1 Journal article |
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Year |
2010 |
Publication |
Superconductor science and technology |
Abbreviated Journal |
Supercond Sci Tech |
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Volume |
23 |
Issue |
11 |
Pages |
115013-115013,8 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
For the first time, the local structure and physical properties of Ru1222 based compounds (RuSr(2)Gd(1.4)Ce(0.6)Cu(2)O(10-delta) and RuSr(2)Gd(1.8-x)Y(0.2)CexCu(2)O(10) (x = 0.90-0.55)) have been investigated and analyzed together on the very same compounds. The Ru1222 superstructure was confirmed by TEM at a local scale and was suggested to have an orthorhombic symmetry with space group Aba2 and lattice parameters a(s) similar or equal to root 2a, b(s) similar or equal to root 2a and c(s) = c. This new Ru1222 superstructure distortion from tetragonal symmetry is proposed to have a positive correlation with the superconductivity variation of these compounds. The more the distortion towards orthorhombic symmetry, the higher the critical superconducting temperature these compounds can achieve. The T(c)(0) of RuSr(2)Gd(1.8-x)Y(0.2)Ce(x)Cu(2)O(10-delta) (x = 0.85-0.55) increases monotonically from 4 to 16 K when x decreases from 0.85 to 0.70, then RuSr(2)Gd(2)Cu(2)O(8) defects emerge and the T(c) decreases with decreasing x. Ru1212 defects are observed to intergrow epitaxially with the Ru1222 structure as lamellas along the c-axis in RuSr(2)Gd(1.4)Ce(0.6)Cu(2)O(10-delta). Although Ru1212 is a superconductor, the intergrowth severely restrains its superconductivity. |
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Place of Publication |
Bristol |
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Wos |
000284308000013 |
Publication Date |
2010-10-09 |
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Abbreviated Series Title |
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ISSN |
0953-2048;1361-6668; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.878 |
Times cited |
1 |
Open Access |
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Notes |
Fwo; Esteem 026019 |
Approved |
Most recent IF: 2.878; 2010 IF: 2.402 |
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Call Number |
UA @ lucian @ c:irua:95553 |
Serial |
3385 |
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Permanent link to this record |
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Author |
Lin, A.G.; Xiang, B.; Merlino, D.J.; Baybutt, T.R.; Sahu, J.; Fridman, A.; Snook, A.E.; Miller, V. |
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Title |
Non-thermal plasma induces immunogenic cell death in vivo in murine CT26 colorectal tumors |
Type |
A1 Journal article |
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Year |
2018 |
Publication |
Oncoimmunology |
Abbreviated Journal |
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Volume |
7 |
Issue |
9 |
Pages |
e1484978 |
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Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Abstract |
Immunogenic cell death is characterized by the emission of danger signals that facilitate activation of an adaptive immune response against dead-cell antigens. In the case of cancer therapy, tumor cells undergoing immunogenic death promote cancer-specific immunity. Identification, characterization, and optimization of stimuli that induce immunogenic cancer cell death has tremendous potential to improve the outcomes of cancer therapy. In this study, we show that non-thermal, atmospheric pressure plasma can be operated to induce immunogenic cell death in an animal model of colorectal cancer. In vitro, plasma treatment of CT26 colorectal cancer cells induced the release of classic danger signals. Treated cells were used to create a whole-cell vaccine which elicited protective immunity in the CT26 tumor mouse model. Moreover, plasma treatment of subcutaneous tumors elicited emission of danger signals and recruitment of antigen presenting cells into tumors. An increase in T cell responses targeting the colorectal cancer-specific antigen guanylyl cyclase C (GUCY2C) were also observed. This study provides the first evidence that non-thermal plasma is a bone fide inducer of immunogenic cell death and highlights its potential for clinical translation for cancer immunotherapy. |
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Wos |
000443993100030 |
Publication Date |
2018-06-12 |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2162-4011; 2162-402x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
28 |
Open Access |
Not_Open_Access |
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Notes |
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Approved |
Most recent IF: NA |
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Call Number |
UA @ lucian @ c:irua:155651 |
Serial |
5119 |
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Permanent link to this record |
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Author |
Rozova, M.G.; Grigoriev, V.V.; Bobrikov, I.A.; Filimonov, D.S.; Zakharov, K.V.; Volkova, O.S.; Vasiliev, A.N.; Antipov, E.V.; Tsirlin, A.A.; Abakumov, A.M. |
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Title |
Synthesis, structure and magnetic ordering of the mullite-type Bi2Fe4-xCrxO9 solid solutions with a frustrated pentagonal Cairo lattice |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Journal of the Chemical Society : Dalton transactions |
Abbreviated Journal |
Dalton T |
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Volume |
45 |
Issue |
45 |
Pages |
1192-1200 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Highly homogeneous mullite-type solid solutions Bi2Fe4-xCrxO9 (x = 0.5, 1, 1.2) were synthesized using a soft chemistry technique followed by a solid-state reaction in Ar. The crystal structure of Bi2Fe3CrO9 was investigated using X-ray and neutron powder diffraction, transmission electron microscopy and Fe-57 Mossbauer spectroscopy (S.G. Pbam, a = 7.95579(9) angstrom , b = 8.39145(9) angstrom, c = 5.98242(7) angstrom, R-F(X-ray) = 0.022, R-F(neutron) = 0.057). The ab planes in the structure are tessellated with distorted pentagonal loops built up by three tetrahedrally coordinated Fe sites and two octahedrally coordinated Fe/Cr sites, linked together in the ab plane by corner-sharing forming a pentagonal Cairo lattice. Magnetic susceptibility measurements and powder neutron diffraction show that the compounds order antiferromagnetically (AFM) with the Neel temperatures decreasing upon increasing the Cr content from T-N similar to 250 K for x = 0 to T-N similar to 155 K for x = 1.2. The magnetic structure of Bi2Fe3CrO9 at T = 30 K is characterized by a propagation vector k = (1/2,1/2,1/2). The tetrahedrally coordinated Fe cations form singlet pairs within dimers of corner-sharing tetrahedra, but spins on the neighboring dimers are nearly orthogonal. The octahedrally coordinated (Fe, Cr) cations form antiferromagnetic up-up-down-down chains along c, while the spin arrangement in the ab plane is nearly orthogonal between nearest neighbors and collinear between second neighbors. The resulting magnetic structure is remarkably different from the one in pure Bi2Fe4O9 and features several types of spin correlations even on crystallographically equivalent exchange that may be caused by the simultaneous presence of Fe and Cr on the octahedral site. |
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Place of Publication |
London |
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Wos |
000367614700041 |
Publication Date |
2015-11-30 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0300-9246; 1477-9226; 1472-7773 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.029 |
Times cited |
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Open Access |
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Notes |
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Approved |
Most recent IF: NA |
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Call Number |
UA @ lucian @ c:irua:131095 |
Serial |
4257 |
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Permanent link to this record |
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Author |
Mikhailova, D.; Reichel, P.; Tsirlin, A.A.; Abakumov, A.M.; Senyshyn, A.; Mogare, K.M.; Schmidt, M.; Kuo, C.Y.; Pao, C.W.; Pi, T.W.; Lee, J.F.; Hu, Z.; Tjeng, L.H.; |
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Title |
Oxygen-driven competition between low-dimensional structures of Sr3CoMO6 and Sr3CoMO7-\delta with M = Ru,Ir |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
Journal of the Chemical Society : Dalton transactions |
Abbreviated Journal |
Dalton T |
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Volume |
43 |
Issue |
37 |
Pages |
13883-13891 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
We have realized a reversible structure transformation of one-dimensional 1D K4CdCl6-type Sr3CoMO6 with the Co2+/M4+ cation ordering into the two-dimensional 2D double layered Ruddlesden-Popper structure Sr3CoMO7-delta with a random distribution of Co and M (with M = Ru, Ir) upon increasing the partial oxygen pressure. The combined soft and hard X-ray absorption spectroscopy studies show that under transformation, Co and M cations were oxidized to Co3+ and M5+. During oxidation, high-spin Co2+ in Sr3CoMO6 first transforms into high-spin Co3+ in oxygen-deficient Sr3CoMO7-delta, and then further transforms into low-spin Co3+ in fully oxidized Sr3CoMO7 upon further increasing the partial pressure of oxygen. The 1D Sr3CoMO6 compound is magnetically ordered at low temperatures with the magnetic moments lying along the c-axis. Their alignment is parallel for Sr3CoRuO6 and antiparallel for Sr3CoIrO6. The 2D compounds reveal a spin-glass-like behavior related to the random distribution of magnetic cations in the structure. |
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Place of Publication |
London |
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Wos |
000342074100009 |
Publication Date |
2014-07-28 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1477-9226;1477-9234; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.029 |
Times cited |
7 |
Open Access |
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Notes |
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Approved |
Most recent IF: 4.029; 2014 IF: 4.197 |
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Call Number |
UA @ lucian @ c:irua:119960 |
Serial |
2545 |
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Permanent link to this record |
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Author |
Yang, T.; Abakumov, A.M.; Hadermann, J.; Van Tendeloo, G.; Nowik, I.; Stephens, P.W.; Hamberger, J.; Tsirlin, A.A.; Ramanujachary, K.V.; Lofland, S.; Croft, M.; Ignatov, A.; Sun, J.; Greenblatt, M. |
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Title |
_BiMnFe2O6, a polysynthetically twinned hcp MO structure |
Type |
A1 Journal article |
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Year |
2010 |
Publication |
Chemical science |
Abbreviated Journal |
Chem Sci |
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Volume |
1 |
Issue |
6 |
Pages |
751-762 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
The most efficient use of spatial volume and the lowest potential energies in the metal oxide structures are based on cubic close packing (ccp) or hexagonal close packing (hcp) of anions with cations occupying the interstices. A promising way to tune the composition of close packed oxides and design new compounds is related to fragmenting the parent structure into modules by periodically spaced planar interfaces, such as twin planes at the unit cell scale. The unique crystal chemistry properties of cations with a lone electron pair, such as Bi3+ or Pb2+, when located at interfaces, enables them to act as chemical scissors, to help relieve configurational strain. With this approach, we synthesized a new oxide, BiMnFe2O6, where fragments of the hypothetical hcp oxygen-based MO structure (the NiAs structure type), for the first time, serve as the building modules in a complex transition metal oxide. Mn3+ and Fe3+ ions are randomly distributed in two crystallographically independent sites (M1 and M2). The structure consists of quasi two-dimensional blocks of the 2H hexagonal close packed MO structure cut along the (114) crystal plane of the hcp lattice and stacked along the c axis. The blocks are related by a mirror operation that allows BiMnFe2O6 to be considered as a polysynthetically twinned 2H hcp MO structure. The transition to an AFM state with an incommensurate spin configuration at [similar] 212 K is established by 57Fe Mössbauer spectroscopy, magnetic susceptibility, specific heat and low temperature powder neutron diffraction. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
Royal Society of Chemistry |
Place of Publication |
Cambridge |
Editor |
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Language |
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Wos |
000283939200013 |
Publication Date |
2010-10-12 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2041-6520;2041-6539; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
8.668 |
Times cited |
12 |
Open Access |
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Notes |
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Approved |
Most recent IF: 8.668; 2010 IF: NA |
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Call Number |
UA @ lucian @ c:irua:85823 |
Serial |
3517 |
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Permanent link to this record |
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Author |
Erni, R.; Abakumov, A.M.; Rossell, M.D.; Batuk, D.; Tsirlin, A.A.; Nénert, G.; Van Tendeloo, G. |
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Title |
Nanoscale phase separation in perovskites revisited |
Type |
L1 Letter to the editor |
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Year |
2014 |
Publication |
Nature materials |
Abbreviated Journal |
Nat Mater |
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Volume |
13 |
Issue |
3 |
Pages |
216-217 |
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Keywords |
L1 Letter to the editor; Electron microscopy for materials research (EMAT) |
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Abstract |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
London |
Editor |
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Language |
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Wos |
000331945200002 |
Publication Date |
2014-02-20 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1476-1122;1476-4660; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
39.737 |
Times cited |
5 |
Open Access |
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Notes |
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Approved |
Most recent IF: 39.737; 2014 IF: 36.503 |
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Call Number |
UA @ lucian @ c:irua:114579 |
Serial |
2270 |
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Permanent link to this record |
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Author |
Marikutsa, A.V.; Rumyantseva, M.N.; Frolov, D.D.; Morozov, I.V.; Boltalin, A.I.; Fedorova, A.A.; Petukhov, I.A.; Yashina, L.V.; Konstantinova, E.A.; Sadovskaya, E.M.; Abakumov, A.M.; Zubavichus, Y.V.; Gaskov, A.M.; |
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Title |
Role of PdOx and RuOy clusters in oxygen exchange between nanocrystalline tin dioxide and the gas phase |
Type |
A1 Journal article |
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Year |
2013 |
Publication |
The journal of physical chemistry: C : nanomaterials and interfaces |
Abbreviated Journal |
J Phys Chem C |
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Volume |
117 |
Issue |
45 |
Pages |
23858-23867 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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Abstract |
The effect of palladium- and ruthenium-based clusters on nanocrystalline tin dioxide interaction with oxygen was studied by temperature-programmed oxygen isotopic exchange with mass-spectrometry detection. The modification of aqueous sol-gel prepared SnO2 by palladium and, to a larger extent, by ruthenium, increases surface oxygen concentration on the materials. The revealed effects on oxygen exchange-lowering the threshold temperature, separation of surface oxygen contribution to the process, increase of heteroexchange rate and oxygen diffusion coefficient, decrease of activation energies of exchange and diffusion-were more intensive for Ru-modified SnO2 than in the case of SnO2/Pd. The superior promoting activity of ruthenium on tin dioxide interaction with oxygen was interpreted by favoring the dissociative O-2 adsorption and increasing the oxygen mobility, taking into account the structure and chemical composition of the modifier clusters. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Washington, D.C. |
Editor |
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Language |
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Wos |
000327110500046 |
Publication Date |
2013-10-04 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1932-7447;1932-7455; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.536 |
Times cited |
20 |
Open Access |
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Notes |
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Approved |
Most recent IF: 4.536; 2013 IF: 4.835 |
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Call Number |
UA @ lucian @ c:irua:112706 |
Serial |
2924 |
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Permanent link to this record |
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Author |
Navulla, A.; Tsirlin, A.A.; Abakumov, A.M.; Shpanchenko, R.V.; Zhang, H.; Dikarev, E.V. |
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Title |
Fluorinated heterometallic \beta-diketonates as volatile single-source precursors for the synthesis of low-valent mixed-metal fluorides |
Type |
A1 Journal article |
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Year |
2011 |
Publication |
Journal of the American Chemical Society |
Abbreviated Journal |
J Am Chem Soc |
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Volume |
133 |
Issue |
4 |
Pages |
692-694 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Hexafluoroacetylacetonates that contain lead and divalent first-row transition metals, PbM(hfac)4 (M = Ni (1), Co (2), Mn (3), Fe (4), and Zn (5)), have been synthesized. Their heterometallic structures are held together by strong Lewis acid−base interactions between metal atoms and diketonate ligands acting in chelating−bridging fashion. Compounds 1−5 are highly volatile and decompose below 350 °C. Fluorinated heterometallic β-diketonates have been used for the first time as volatile single-source precursors for the preparation of mixed-metal fluorides. Complex fluorides of composition Pb2MF6 have been obtained by decomposition of 1−5 in a two-zone furnace under low-pressure nitrogen flow. Lead−transition metal fluorides conform to orthorhombically distorted Aurivillius-type structure with layers of corner-sharing [MF6] octahedra separated by α-PbO-type (Pb2F2) blocks. Pb2NiF6 and Pb2CoF6 were found to exhibit magnetic ordering below 80 and 43 K, respectively. The ordering is antiferromagnetic, with a weak, uncompensated moment due to the canting of spins. The Pb2MF6 fluorides represent a new class of prospective magnetoelectric materials combining transition metals and lone-pair main-group cations. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Washington, D.C. |
Editor |
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Language |
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Wos |
000287295300015 |
Publication Date |
2010-12-21 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0002-7863;1520-5126; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
13.858 |
Times cited |
28 |
Open Access |
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Notes |
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Approved |
Most recent IF: 13.858; 2011 IF: 9.907 |
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Call Number |
UA @ lucian @ c:irua:88820 |
Serial |
1236 |
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Permanent link to this record |
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Author |
Charkin, D.O.; Demchyna, R.; Prots, Y.; Borrmann, H.; Burkhardt, U.; Schwarz, U.; Schnelle, W.; Plokhikh, I.V.; Kazakov, S.M.; Abakumov, A.M.; Batuk, D.; Verchenko, V.Y.; Tsirlin, A.A.; Curfs, C.; Grin, Y.; Shevelkov, A.V.; |
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Title |
Two New Arsenides, Eu7Cu44As23 and Sr7Cu44As23, With a New Filled Variety of the BaHg11 Structure |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
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Volume |
53 |
Issue |
20 |
Pages |
11173-11184 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Two new ternary arsenides, namely, Eu7Cu44As23 and Sr7Cu44As23, were synthesized from elements at 800 degrees C. Their crystal structure represents a new filled version of the BaHg11 motif with cubic voids alternately occupied by Eu(Sr) and As atoms, resulting in a 2 x 2 x 2 superstructure of the aristotype: space group Fm (3) over barm, a = 16.6707(2) angstrom and 16.7467(2) angstrom, respectively. The Eu derivative exhibits ferromagnetic ordering below 17.5 K. In agreement with band structure calculations both compounds are metals, exhibiting relatively low thermopower, but high electrical and low thermal conductivity. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Easton, Pa |
Editor |
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Language |
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Wos |
000343527700049 |
Publication Date |
2014-09-29 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0020-1669;1520-510X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.857 |
Times cited |
9 |
Open Access |
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Notes |
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Approved |
Most recent IF: 4.857; 2014 IF: 4.762 |
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Call Number |
UA @ lucian @ c:irua:121141 |
Serial |
3784 |
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Permanent link to this record |
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Author |
Abakumov, A.M.; Morozov, V.A.; Tsirlin, A.A.; Verbeeck, J.; Hadermann, J. |
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Title |
Cation ordering and flexibility of the BO42- tetrahedra in incommensurately modulated CaEu2(BO4)4 (B = Mo, W) scheelites |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
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Volume |
53 |
Issue |
17 |
Pages |
9407-9415 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
The factors mediating cation ordering in the scheelite-based molybdates and tungstates are discussed on the basis of the incommensurately modulated crystal structures of the CaEu2(BO4)(4) (B = Mo, W) red phosphors solved from high-resolution synchrotron powder X-ray diffraction data. Monoclinic CaEu2(WO4)(4) adopts a (3 + 1)-dimensionally modulated structure [superspace group I2/b(alpha beta 0)00, a = 5.238 73(1)A, b = 5.266 35(1) A, c = 11.463 19(9) A, gamma = 91.1511(2)degrees, q = 0.56153(6)a* + 0.7708(9)b*, R-F = 0.050, R-p = 0.069], whereas tetragonal CaEu2(MoO4)(4) is (3 + 2)-dimensionally modulated [superspace group I4(1)/ a(alpha beta 0)00(-beta alpha 0)00, a = 5.238 672(7) A, c = 11.548 43(2) A, q(1) = 035331(8)a* + 0.82068(9)b*, q(2) = -0.82068(9)a* + 0.55331(8)b*, R-F = 0.061, R-p = 0.082]. In both cases the modulation arises from the ordering of the Ca/Eu cations and the cation vacancies at the A-sublattice of the parent scheelite ABO(4) structure. The cation ordering is incomplete and better described with harmonic rather than with steplike occupational modulation functions. The structures respond to the variation of the effective charge and cation size at the A-position through the flexible geometry of the MoO42- and WO42- tetrahedra demonstrating an alternation of stretching the B-O bond lengths and bending the O-B-O bond angles. The tendency towards A-site cation ordering in scheelites is rationalized using the difference in ionic radii and concentration of the A-site vacancies as parameters and presented in the form of a structure map. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Easton, Pa |
Editor |
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Language |
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Wos |
000341229600068 |
Publication Date |
2014-08-21 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0020-1669;1520-510X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.857 |
Times cited |
48 |
Open Access |
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Notes |
Fwo G039211n |
Approved |
Most recent IF: 4.857; 2014 IF: 4.762 |
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Call Number |
UA @ lucian @ c:irua:119292UA @ admin @ c:irua:119292 |
Serial |
297 |
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Permanent link to this record |
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Author |
Batuk, D.; Batuk, M.; Abakumov, A.M.; Tsirlin, A.A.; McCammon, C.M.; Dubrovinsky, L.; Hadermann, J. |
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Title |
Effect of lone-electron-pair cations on the orientation of crystallographic shear planes in anion-deficient perovskites |
Type |
A1 Journal article |
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Year |
2013 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
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Volume |
52 |
Issue |
17 |
Pages |
10009-10020 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Factors affecting the structure and orientation of the crystallographic shear (CS) planes in anion-deficient perovskites are investigated using the (Pb1−zSrz)1−xFe1+xO3−y perovskites as a model system. The orientation of the CS planes in the system varies unevenly with z. A comparison of the structures with different CS planes revels that the orientation of the CS planes is governed mainly by the stereochemical activity of the lone-electron-pair cations inside the perovskite blocks. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Easton, Pa |
Editor |
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Language |
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Wos |
000326129000037 |
Publication Date |
2013-08-22 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0020-1669;1520-510X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.857 |
Times cited |
11 |
Open Access |
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Notes |
Fwo |
Approved |
Most recent IF: 4.857; 2013 IF: 4.794 |
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Call Number |
UA @ lucian @ c:irua:111394 |
Serial |
822 |
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Permanent link to this record |
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Author |
Batuk, M.; Batuk, D.; Tsirlin, A.A.; Rozova, M.G.; Antipov, E.V.; Hadermann, J.; Van Tendeloo, G. |
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Title |
Homologous series of layered perovskites An+1BnO3n-1Cl : crystal and magnetic structure of a new oxychloride Pb4BiFe4O11Cl |
Type |
A1 Journal article |
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Year |
2013 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
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Volume |
52 |
Issue |
4 |
Pages |
2208-2218 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
The nuclear and magnetic structure of a novel oxychloride Pb4BiFe4O11Cl has been studied over the temperature range 1.5700 K using a combination of transmission electron microscopy and synchrotron and neutron powder diffraction [space group P4/mbm, a = 5.5311(1) Å, c = 19.586(1) Å, T = 300 K]. Pb4BiFe4O11Cl is built of truncated (Pb,Bi)3Fe4O11 quadruple perovskite blocks separated by CsCl-type (Pb,Bi)2Cl slabs. The perovskite blocks consist of two layers of FeO6 octahedra located between two layers of FeO5 tetragonal pyramids. The FeO6 octahedra rotate about the c axis, resulting in a √2ap × √2ap × c superstructure. Below TN = 595(17) K, Pb4BiFe4O11Cl adopts a G-type antiferromagnetic structure with the iron magnetic moments confined to the ab plane. The ordered magnetic moments at 1.5 K are 3.93(3) and 3.62(4) μB on the octahedral and square-pyramidal iron sites, respectively. Pb4BiFe4O11Cl can be considered a member of the perovskite-based An+1BnO3n1Cl homologous series (A = Pb/Bi; B = Fe) with n = 4. The formation of a subsequent member of the series with n = 5 is also demonstrated. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Easton, Pa |
Editor |
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Language |
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Wos |
000315255200067 |
Publication Date |
2013-02-05 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0020-1669;1520-510X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.857 |
Times cited |
6 |
Open Access |
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Notes |
Countatoms |
Approved |
Most recent IF: 4.857; 2013 IF: 4.794 |
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Call Number |
UA @ lucian @ c:irua:106185 |
Serial |
1486 |
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Permanent link to this record |
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Author |
Abakumov, A.M.; Batuk, M.; Tsirlin, A.A.; Tyablikov, O.A.; Sheptyakov, D.V.; Filimonov, D.S.; Pokholok, K.V.; Zhidal, V.S.; Rozova, M.G.; Antipov, E.V.; Hadermann, J.; Van Tendeloo, G.; |
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Title |
Structural and magnetic phase transitions in the AnBnO3n-2 anion-deficient perovskites Pb2Ba2BiFe5O13 and Pb1.5Ba2.5Bi2Fe6O16 |
Type |
A1 Journal article |
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Year |
2013 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
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Volume |
52 |
Issue |
14 |
Pages |
7834-7843 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Novel anion-deficient perovskite-based ferrites Pb2Ba2BiFe5O13 and Pb1.5Ba2.5Bi2Fe6O16 were synthesized by solid-state reaction in air. Pb2Ba2BiFe5O13 and Pb1.5Ba2.5Bi2Fe6O16 belong to the perovskite-based AnBnO3n2 homologous series with n = 5 and 6, respectively, with a unit cell related to the perovskite subcell ap as ap√2 × ap × nap√2. Their structures are derived from the perovskite one by slicing it with 1/2[110]p(1̅01)p crystallographic shear (CS) planes. The CS operation results in (1̅01)p-shaped perovskite blocks with a thickness of (n 2) FeO6 octahedra connected to each other through double chains of edge-sharing FeO5 distorted tetragonal pyramids which can adopt two distinct mirror-related configurations. Ordering of chains with a different configuration provides an extra level of structure complexity. Above T ≈ 750 K for Pb2Ba2BiFe5O13 and T ≈ 400 K for Pb1.5Ba2.5Bi2Fe6O16 the chains have a disordered arrangement. On cooling, a second-order structural phase transition to the ordered state occurs in both compounds. Symmetry changes upon phase transition are analyzed using a combination of superspace crystallography and group theory approach. Correlations between the chain ordering pattern and octahedral tilting in the perovskite blocks are discussed. Pb2Ba2BiFe5O13 and Pb1.5Ba2.5Bi2Fe6O16 undergo a transition into an antiferromagnetically (AFM) ordered state, which is characterized by a G-type AFM ordering of the Fe magnetic moments within the perovskite blocks. The AFM perovskite blocks are stacked along the CS planes producing alternating FM and AFM-aligned FeFe pairs. In spite of the apparent frustration of the magnetic coupling between the perovskite blocks, all n = 4, 5, 6 AnFenO3n2 (A = Pb, Bi, Ba) feature robust antiferromagnetism with similar Néel temperatures of 623632 K. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Easton, Pa |
Editor |
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Language |
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Wos |
000322087100006 |
Publication Date |
2013-02-13 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0020-1669;1520-510X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.857 |
Times cited |
10 |
Open Access |
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Notes |
Countatoms |
Approved |
Most recent IF: 4.857; 2013 IF: 4.794 |
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Call Number |
UA @ lucian @ c:irua:109213 |
Serial |
3196 |
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Permanent link to this record |
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Author |
Hadermann, J.; Abakumov, A.M.; Tsirlin, A.A.; Rozova, M.G.; Sarakinou, E.; Antipov, E.V. |
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Title |
Expanding the Ruddlesden-Popper manganite family : the n=3 La3.2Ba0.8Mn3O10 Member |
Type |
A1 Journal article |
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Year |
2012 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
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Volume |
51 |
Issue |
21 |
Pages |
11487-11492 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
La3.2Ba0.8Mn3O10, a representative of the rare n = 3 members of the Ruddlesden-Popper manganites A(n+1)Mn(n)O(3n+1), was synthesized in an evacuated sealed silica tube. Its crystal structure was refined from a combination of powder X-ray diffraction (PXD) and precession electron diffraction (PED) data, with the rotations of the MnO6 octahedra described within the symmetry-adapted mode approach (space group Cccm, a = 29.068(1) angstrom, b = 5.5504(5) angstrom, c = 5.5412(5) angstrom; PXD RF = 0.053, RP = 0.026; PED RF = 0.248). The perovskite block in La3.2Ba0.8Mn3O10 features an octahedral tilting distortion with out-of-phase rotations of the Mn06 octahedra according to the (Phi,Phi,0)(Phi,Phi,0) mode, observed for the first time in the n = 3 Ruddlesden-Popper structures. The Mn06 octahedra demonstrate a noticeable deformation with the elongation of two apical Mn-O bonds due to the Jahn-Teller effect in the Mn3+ cations. The relationships between the octahedral tilting distortion, the ionic radii of the cations at the A- and B-positions, and the mismatch between the perovslcite and rock-salt blocks of the Ruddlesden-Popper structure are discussed. At low temperatures, La3.2Ba0.8Mn3O10 reveals a sizable remnant magnetization of about 1.3 mu(B)/Mn at 2K, and shows signatures of spin freezing below 150 K. |
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Place of Publication |
Easton, Pa |
Editor |
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Language |
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Wos |
000313220200036 |
Publication Date |
2012-10-17 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0020-1669;1520-510X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.857 |
Times cited |
2 |
Open Access |
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|
Notes |
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Approved |
Most recent IF: 4.857; 2012 IF: 4.593 |
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Call Number |
UA @ lucian @ c:irua:110121 |
Serial |
1133 |
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Permanent link to this record |
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Author |
King, G.; Abakumov, A.M.; Woodward, P.M.; Llobet, A.; Tsirlin, A.A.; Batuk, D.; Antipov, E.V. |
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Title |
The high-temperature polymorphs of K3AlF6 |
Type |
A1 Journal article |
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Year |
2011 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
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Volume |
50 |
Issue |
16 |
Pages |
7792-7801 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
The crystal structures of the three high-temperature polymorphs of K3AlF6 have been solved from neutron powder diffraction, synchrotron X-ray powder diffraction, and electron diffraction data. The β-phase (stable between 132 and 153 °C) and γ-phase (stable between 153 to 306 °C) can be described as unusually complex superstructures of the double-perovskite structure (K2KAlF6) which result from noncooperative tilting of the AlF6 octahedra. The β-phase is tetragonal, space group I4/m, with lattice parameters of a = 13.3862(5) Å and c = 8.5617(3) Å (at 143 °C) and Z = 10. In this phase, one-fifth of the AlF6 octahedra are rotated about the c-axis by 45° while the other four-fifths remain untilted. The large 45° rotations result in edge sharing between these AlF6 octahedra and the neighboring K-centered polyhedra, resulting in pentagonal bipyramidal coordination for four-fifths of the K+ ions that reside on the B-sites of the perovskite structure. The remaining one-fifth of the K+ ions on the B-sites retain octahedral coordination. The γ-phase is orthorhombic, space group Fddd, with lattice parameters of a = 36.1276(4) Å, b = 17.1133(2) Å, and c = 12.0562(1) Å (at 225 °C) and Z = 48. In the γ-phase, one-sixth of the AlF6 octahedra are randomly rotated about one of two directions by 45° while the other five-sixths remain essentially untilted. These rotations result in two-thirds of the K+ ions on the B-site obtaining 7-fold coordination while the other one-third remain in octahedral coordination. The δ-phase adopts the ideal cubic double-perovskite structure, space group Fmm, with a = 8.5943(1) Å at 400 °C. However, pair distribution function analysis shows that locally the δ-phase is quite different from its long-range average crystal structure. The AlF6 octahedra undergo large-amplitude rotations which are accompanied by off-center displacements of the K+ ions that occupy the 12-coordinate A-sites. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Easton, Pa |
Editor |
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Language |
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Wos |
000293493100052 |
Publication Date |
2011-07-11 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0020-1669;1520-510X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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|
Impact Factor |
4.857 |
Times cited |
19 |
Open Access |
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|
Notes |
|
Approved |
Most recent IF: 4.857; 2011 IF: 4.601 |
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Call Number |
UA @ lucian @ c:irua:91131 |
Serial |
1468 |
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Permanent link to this record |
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Author |
Abakumov, A.M.; Hadermann, J.; Batuk, M.; d' Hondt, H.; Tyablikov, O.A.; Rozova, M.G.; Pokholok, K.V.; Filimonov, D.S.; Sheptyakov, D.V.; Tsirlin, A.A.; Niermann, D.; Hemberger, J.; Van Tendeloo, G.; Antipov, E.V. |
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Title |
Slicing the Perovskite structure with crystallographic shear planes : the AnBnO3n-2 homologous series |
Type |
A1 Journal article |
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Year |
2010 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
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Volume |
49 |
Issue |
20 |
Pages |
9508-9516 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
A new AnBnO3n−2 homologous series of anion-deficient perovskites has been evidenced by preparation of the members with n = 5 (Pb2.9Ba2.1Fe4TiO13) and n = 6 (Pb3.8Bi0.2Ba2Fe4.2Ti1.8O16) in a single phase form. The crystal structures of these compounds were determined using a combination of transmission electron microscopy and X-ray and neutron powder diffraction (S.G. Ammm, a = 5.74313(7), b = 3.98402(4), c = 26.8378(4) Å, RI = 0.035, RP = 0.042 for Pb2.9Ba2.1Fe4TiO13 and S.G. Imma, a = 5.7199(1), b = 3.97066(7), c = 32.5245(8) Å, RI = 0.032, RP = 0.037 for Pb3.8Bi0.2Ba2Fe4.2Ti1.8O16). The crystal structures of the AnBnO3n−2 homologues are formed by slicing the perovskite structure with (01)p crystallographic shear (CS) planes. The shear planes remove a layer of oxygen atoms and displace the perovskite blocks with respect to each other by the 1/2[110]p vector. The CS planes introduce edge-sharing connections of the transition metal−oxygen polyhedra at the interface between the perovskite blocks. This results in intrinsically frustrated magnetic couplings between the perovskite blocks due to a competition of the exchange interactions between the edge- and the corner-sharing metal−oxygen polyhedra. Despite the magnetic frustration, neutron powder diffraction and Mssbauer spectroscopy reveal that Pb2.9Ba2.1Fe4TiO13 and Pb3.8Bi0.2Ba2Fe4.2Ti1.8O16 are antiferromagnetically ordered below TN = 407 and 343 K, respectively. The Pb2.9Ba2.1Fe4TiO13 and Pb3.8Bi0.2Ba2Fe4.2Ti1.8O16 compounds are in a paraelectric state in the 5−300 K temperature range. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Easton, Pa |
Editor |
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Language |
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Wos |
000282783400051 |
Publication Date |
2010-09-24 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0020-1669;1520-510X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.857 |
Times cited |
23 |
Open Access |
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Notes |
Esteem 026019; Fwo |
Approved |
Most recent IF: 4.857; 2010 IF: 4.326 |
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Call Number |
UA @ lucian @ c:irua:84963 |
Serial |
3041 |
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Permanent link to this record |
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Author |
Abakumov, A.M.; Tsirlin, A.A.; Bakaimi, I.; Van Tendeloo, G.; Lappas, A. |
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Title |
Multiple twinning as a structure directing mechanism in layered rock-salt-type oxides : NaMnO2 polymorphism, redox potentials, and magnetism |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
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Volume |
26 |
Issue |
10 |
Pages |
3306-3315 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
New polymorphs of NaMnO2 have been observed using transmission electron microscopy and synchrotron X-ray powder diffraction. Coherent twin planes confined to the (NaMnO2) layers, parallel to the (10 (1) over bar) crystallographic planes of the monoclinic layered rock-salt-type alpha-NaMnO2 (O3) structure, form quasi-periodic modulated sequences, with the known alpha-and beta-NaMnO2 polymorphs as the two limiting cases. The energy difference between the polymorphic forms, estimated using a DFT-based structure relaxation, is on the scale of the typical thermal energies that results in a high degree of stacking disorder in these compounds. The results unveil the remarkable effect of the twin planes on both the magnetic and electrochemical properties. The polymorphism drives the magnetic ground state from a quasi-1D spin system for the geometrically frustrated alpha-polymorph through a two-leg spin ladder for the intermediate stacking sequence toward a quasi-2D magnet for the beta-polymorph. A substantial increase of the equilibrium potential for Na deintercalation upon increasing the concentration of the twin planes is calculated, providing a possibility to tune the electrochemical potential of the layered rock-salt ABO(2) cathodes by engineering the materials with a controlled concentration of twins. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000336637000036 |
Publication Date |
2014-05-01 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0897-4756;1520-5002; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
9.466 |
Times cited |
35 |
Open Access |
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Notes |
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Approved |
Most recent IF: 9.466; 2014 IF: 8.354 |
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Call Number |
UA @ lucian @ c:irua:117766 |
Serial |
2232 |
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Permanent link to this record |
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Author |
Abakumov, A.M.; Erni, R.; Tsirlin, A.A. |
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Title |
Reply to Comment on “Frustrated octahedral tilting distortion in the incommensurately modulated Li3xNd2/3-xTiO3 perovskites” |
Type |
Editorial |
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Year |
2014 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
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Volume |
26 |
Issue |
2 |
Pages |
1288 |
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Keywords |
Editorial; Electron microscopy for materials research (EMAT) |
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Abstract |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Washington, D.C. |
Editor |
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Language |
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Wos |
000330543600051 |
Publication Date |
2014-01-03 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0897-4756;1520-5002; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
|
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Impact Factor |
9.466 |
Times cited |
1 |
Open Access |
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Notes |
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Approved |
Most recent IF: 9.466; 2014 IF: 8.354 |
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Call Number |
UA @ lucian @ c:irua:115730 |
Serial |
2874 |
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Permanent link to this record |
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Author |
Abakumov, A.M.; Erni, R.; Tsirlin, A.A.; Rossell, M.D.; Batuk, D.; Nénert, G.; Van Tendeloo, G. |
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Title |
Frustrated octahedral tilting distortion in the incommensurately modulated Li3xNd2/3-xTiO3 perovskites |
Type |
A1 Journal article |
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Year |
2013 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
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Volume |
25 |
Issue |
13 |
Pages |
2670-2683 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Perovskite-structured titanates with layered A-site ordering form remarkably complex superstructures. Using transmission electron microscopy, synchrotron X-ray and neutron powder diffraction, and ab initio structure relaxation, we present the structural solution of the incommensurately modulated Li3xNd2/3xTiO3 perovskites (x = 0.05, superspace group Pmmm(α1,1/2,0)000(1/2,β2 0)000, a = 3.831048(5) Å, b = 3.827977(4) Å, c = 7.724356(8) Å, q1 = 0.45131(8)a* + 1/2b*, q2 = 1/2a* + 0.41923(4)b*). In contrast to earlier conjectures on the nanoscale compositional phase separation in these materials, all peculiarities of the superstructure can be understood in terms of displacive modulations related to an intricate octahedral tilting pattern. It involves fragmenting the pattern of the out-of-phase tilted TiO6 octahedra around the a- and b-axes into antiphase domains, superimposed on the pattern of domains with either pronounced or suppressed in-phase tilt component around the c-axis. The octahedral tilting competes with the second order JahnTeller distortion of the TiO6 octahedra. This competition is considered as the primary driving force for the modulated structure. The A cations are suspected to play a role in this modulation affecting it mainly through the tolerance factor and the size variance. The reported crystal structure calls for a revision of the structure models proposed for the family of layered A-site ordered perovskites exhibiting a similar type of modulated structure. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Washington, D.C. |
Editor |
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Language |
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Wos |
000321809700015 |
Publication Date |
2013-06-04 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0897-4756;1520-5002; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
9.466 |
Times cited |
23 |
Open Access |
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Notes |
Countatoms |
Approved |
Most recent IF: 9.466; 2013 IF: 8.535 |
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Call Number |
UA @ lucian @ c:irua:109216 |
Serial |
1292 |
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Permanent link to this record |
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Author |
Dachraoui, W.; Hadermann, J.; Abakumov, A.M.; Tsirlin, A.A.; Batuk, D.; Glazyrin, K.; McCammon, C.; Dubrovinsky, L.; Van Tendeloo, G. |
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Title |
Local oxygen-vacancy ordering and twinned octahedral tilting pattern in the Bi0.81Pb0.19FeO2.905 cubic perovskite |
Type |
A1 Journal article |
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Year |
2012 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
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Volume |
24 |
Issue |
7 |
Pages |
1378-1385 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
The structure of Bi0.81Pb0.19FeO2.905 was investigated on different length scales using a combination of electron diffraction, high-resolution scanning transmission electron microscopy, synchrotron X-ray powder diffraction, and Mössbauer spectroscopy. In the 80300 K temperature range, the average crystal structure of Bi0.81Pb0.19FeO2.905 is a cubic Pm3̅m perovskite with a = 3.95368(3) Å at T = 300 K. The (Pb2+, Bi3+) cations and O2 anions are randomly displaced along the 110 cubic directions, indicating the steric activity of the lone pair on the Pb2+ and Bi3+ cations and a tilting distortion of the perovskite framework. The charge imbalance induced by the heterovalent Bi3+ → Pb2+ substitution is compensated by the formation of oxygen vacancies preserving the trivalent state of the Fe cations. On a short scale, oxygen vacancies are located in anion-deficient (FeO1.25) layers that are approximately 6 perovskite unit cells apart and transform every sixth layer of the FeO6 octahedra into a layer with a 1:1 mixture of corner-sharing FeO4 tetrahedra and FeO5 tetragonal pyramids. The anion-deficient layers act as twin planes for the octahedral tilting pattern of adjacent perovskite blocks. They effectively randomize the octahedral tilting and prevent the cooperative distortion of the perovskite framework. The disorder in the anion sublattice impedes cooperative interactions of the local dipoles induced by the off-center displacements of the Pb and Bi cations. Magnetic susceptibility measurements evidence the antiferromagnetic ordering in Bi0.81Pb0.19FeO2.905 at low temperatures. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Washington, D.C. |
Editor |
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Language |
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Wos |
000302487500018 |
Publication Date |
2012-03-13 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0897-4756;1520-5002; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
9.466 |
Times cited |
27 |
Open Access |
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Notes |
|
Approved |
Most recent IF: 9.466; 2012 IF: 8.238 |
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Call Number |
UA @ lucian @ c:irua:97389 |
Serial |
1829 |
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Permanent link to this record |
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Author |
Belik, A.A.; Abakumov, A.M.; Tsirlin, A.A.; Hadermann, J.; Kim, J.; Van Tendeloo, G.; Takayama-Muromachi, E. |
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Title |
Article Structure and magnetic properties of BiFe0.75Mn0.25O3 perovskite prepared at ambient and high pressure |
Type |
A1 Journal article |
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Year |
2011 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
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Volume |
23 |
Issue |
20 |
Pages |
4505-4514 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Solid solutions of BiFe1xMnxO3 (0.0 ≤ x ≤ 0.4) were prepared at ambient pressure and at 6 GPa. The ambient-pressure (AP) phases crystallize in space group R3c similarly to BiFeO3. The high-pressure (HP) phases crystallize in space group R3c for x = 0.05 and in space group Pnma for 0.15 ≤ x ≤ 0.4. The structure of HP-BiFe0.75Mn0.25O3 was investigated using synchrotron X-ray powder diffraction, electron diffraction, and transmission electron microscopy. HP-BiFe0.75Mn0.25O3 has a PbZrO3-related √2ap × 4ap × 2√2ap (ap is the parameter of the cubic perovskite subcell) superstructure with a = 5.60125(9) Å, b = 15.6610(2) Å, and c = 11.2515(2) Å similar to that of Bi0.82La0.18FeO3. A remarkable feature of this structure is the unconventional octahedral tilt system, with the primary ab0a tilt superimposed on pairwise clockwise and counterclockwise rotations around the b-axis according to the oioi sequence (o stands for out-of-phase tilt, and i stands for in-phase tilt). The (FeMn)O6 octahedra are distorted, with one longer metaloxygen bond (2.222.23 Å) that can be attributed to a compensation for covalent BiO bonding. Such bonding results in the localization of the lone electron pair on Bi3+ cations, as confirmed by electron localization function analysis. The relationship between HP-BiFe0.75Mn0.25O3 and antiferroelectric structures of PbZrO3 and NaNbO3 is discussed. On heating in air, HP-BiFe0.75Mn0.25O3 irreversibly transforms to AP-BiFe0.75Mn0.25O3 starting from about 600 K. Both AP and HP phases undergo an antiferromagnetic ordering at TN ≈ 485 and 520 K, respectively, and develop a weak net magnetic moment at low temperatures. Additionally, ceramic samples of AP-BiFe0.75Mn0.25O3 show a peculiar phenomenon of magnetization reversal. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Washington, D.C. |
Editor |
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Language |
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Wos |
000295897400015 |
Publication Date |
2011-09-29 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0897-4756;1520-5002; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
9.466 |
Times cited |
57 |
Open Access |
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Notes |
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Approved |
Most recent IF: 9.466; 2011 IF: 7.286 |
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Call Number |
UA @ lucian @ c:irua:93581 |
Serial |
151 |
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Permanent link to this record |
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Author |
Kazakov, S.M.; Abakumov, A.M.; Perz-Mato, J.M.; Ovchinnikov, A.V.; Roslova, M.V.; Boltalin, A.I.; Morozov, I.V.; Antipov, E.V.; Van Tendeloo, G. |
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Title |
Uniform patterns of Fe-vacancy ordering in the Kx(Fe,Co)2-ySe2 superconductors |
Type |
A1 Journal article |
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Year |
2011 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
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Volume |
23 |
Issue |
19 |
Pages |
4311-4316 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
The Fe-vacancy ordering patterns in the superconducting KxFe2ySe2 and nonsuperconducting Kx(Fe,Co)2ySe2 samples have been investigated by electron diffraction and high angle annular dark field scanning transmission electron microscopy. The Fe-vacancy ordering occurs in the ab plane of the parent ThCr2Si2-type structure, demonstrating two types of patterns. Superstructure I retains the tetragonal symmetry and can be described with the aI = bI = as√5 (as is the unit cell parameter of the parent ThCr2Si2-type structure) supercell and I4/m space group. Superstructure II reduces the symmetry to orthorhombic with the aII = as√2, bII = 2as√2 supercell and the Ibam space group. This type of superstructure is observed for the first time in KxFe2ySe2. The Fe-vacancy ordering is inhomogeneous: the disordered areas interleave with the superstructures I and II in the same crystallite. The observed superstructures represent the compositionally dependent uniform ordering patterns of two species (the Fe atoms and vacancies) on a square lattice. More complex uniform ordered configurations, including compositional stripes, can be predicted for different chemical compositions of the KxFe2ySe2 (0 < y < 0.5) solid solutions. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Washington, D.C. |
Editor |
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Language |
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Wos |
000295487800005 |
Publication Date |
2011-09-13 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0897-4756;1520-5002; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
9.466 |
Times cited |
20 |
Open Access |
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Notes |
|
Approved |
Most recent IF: 9.466; 2011 IF: 7.286 |
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Call Number |
UA @ lucian @ c:irua:92805 |
Serial |
3810 |
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Permanent link to this record |
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Author |
Abakumov, A.M.; Batuk, D.; Hadermann, J.; Rozova, M.G.; Sheptyakov, D.V.; Tsirlin, A.A.; Niermann, D.; Waschowski, F.; Hemberger, J.; Van Tendeloo, G.; Antipov, E.V. |
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Title |
Antiferroelectric (Pb,Bi)1-xFe1+xO3-y perovskites modulated by crystallographic shear planes |
Type |
A1 Journal article |
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Year |
2011 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
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Volume |
23 |
Issue |
2 |
Pages |
255-265 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
We demonstrate for the first time a possibility to vary the anion content in perovskites over a wide range through a long-range-ordered arrangement of crystallographic shear (CS) planes. Anion-deficient perovskites (Pb,Bi)1−xFe1+xO3−y with incommensurately modulated structures were prepared as single phases in the compositional range from Pb0.857Bi0.094Fe1.049O2.572 to Pb0.409Bi0.567Fe1.025O2.796. Using a combination of electron diffraction and high-resolution scanning transmission electron microscopy, we constructed a superspace model describing a periodic arrangement of the CS planes. The model was verified by refinement of the Pb0.64Bi0.32Fe1.04O2.675 crystal structure from neutron powder diffraction data ((3 + 1)D S.G. X2/m(α0γ), X = [1/2,1/2,1/2,1/2], a = 3.9082(1) Å, b = 3.90333(8) Å, c = 4.0900(1) Å, β = 91.936(2)°, q = 0.05013(4)a* + 0.09170(3)c* at T = 700 K, RP = 0.036, RwP = 0.048). The (Pb,Bi)1−xFe1+xO3−y structures consist of perovskite blocks separated by CS planes confined to nearly the (509)p perovskite plane. Along the CS planes, the perovskite blocks are shifted with respect to each other over the 1/2[110]p vector that transforms the corner-sharing connectivity of the FeO6 octahedra in the perovskite framework to an edge-sharing connectivity of the FeO5 pyramids at the CS plane, thus reducing the oxygen content. Variation of the chemical composition in the (Pb,Bi)1−xFe1+xO3−y series occurs mainly because of a changing thickness of the perovskite block between the interfaces, that can be expressed through the components of the q vector as Pb6γ+2αBi1−7γ−αFe1+γ−αO3−3γ−α. The Pb, Bi, and Fe atoms are subjected to strong displacements occurring in antiparallel directions on both sides of the perovskite blocks, resulting in an antiferroelectric-type structure. This is corroborated by the temperature-, frequency-, and field-dependent complex permittivity measurements. Pb0.64Bi0.32Fe1.04O2.675 demonstrates a remarkably high resistivity >0.1 T Ω cm at room temperature and orders antiferromagnetically below TN = 608(10) K. |
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Washington, D.C. |
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Wos |
000286160800018 |
Publication Date |
2010-12-23 |
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0897-4756;1520-5002; |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
9.466 |
Times cited |
29 |
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Approved |
Most recent IF: 9.466; 2011 IF: 7.286 |
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Call Number |
UA @ lucian @ c:irua:88651 |
Serial |
136 |
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Author |
Fedoseeva, Y.V.; Orekhov, A.S.; Chekhova, G.N.; Koroteev, V.O.; Kanygin, M.A.; Seovskiy, B.V.; Chuvilin, A.; Pontiroli, D.; Ricco, M.; Bulusheva, L.G.; Okotrub, A.V. |
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Single-walled carbon nanotube reactor for redox transformation of mercury dichloride |
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A1 Journal article |
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Year |
2017 |
Publication |
ACS nano |
Abbreviated Journal |
Acs Nano |
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11 |
Issue |
9 |
Pages |
8643-8649 |
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A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
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<script type='text/javascript'>document.write(unpmarked('Single-walled carbon nanotubes (SWCNTs) possessing a confined inner space protected by chemically resistant shells are promising for delivery, storage, and desorption of various compounds, as well as carrying out specific reactions. Here, we show that SWCNTs interact with molten mercury dichloride (HgCl2) and guide its transformation into dimercury dichloride (Hg2Cl2) in the cavity. The chemical state of host SWCNTs remains almost unchanged except for a small p-doping from the guest Hg2Cl2 nanocrystals. The density functional theory calculations reveal that the encapsulated HgCl2 molecules become negatively charged and start interacting via chlorine bridges when local concentration increases. This reduces the bonding strength in HgCl2, which facilitates removal of chlorine, finally leading to formation of Hg2Cl2 species. The present work demonstrates that SWCNTs not only serve as a template for growing nanocrystals but also behave as an electron-transfer catalyst in the spatially confined redox reaction by donation of electron density for temporary use by the guests.')); |
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000411918200012 |
Publication Date |
2017-08-07 |
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1936-0851 |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
13.942 |
Times cited |
11 |
Open Access |
Not_Open_Access |
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Notes |
; Collaboration between partner institutions was partially supported by European FP7 IRSES project 295180. We are grateful to the bilateral Program “Russian-German Laboratory at BESSY II” for the assistance in XPS and NEXAFS measurements. We acknowledge C. Tollan for proofreading the manuscript. We are grateful to Dr. Y.V. Shubin for XRD measurements of graphite with HgCl<INF>2</ INF>. ; |
Approved |
Most recent IF: 13.942 |
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Call Number |
UA @ lucian @ c:irua:146770 |
Serial |
4895 |
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