|
Records |
Links |
|
Author ![sorted by Author field, ascending order (up)](img/sort_asc.gif) |
Tunca, B.; Lapauw, T.; Delville, R.; Neuville, D.R.; Hennet, L.; Thiaudiere, D.; Ouisse, T.; Hadermann, J.; Vleugels, J.; Lambrinou, K. |
![goto web page (via DOI) doi](http://nano.uantwerpen.be/nanorefs/img/doi.gif)
|
|
Title |
Synthesis and Characterization of Double Solid Solution (Zr,Ti)(2)(Al,Sn)C MAX Phase Ceramics |
Type |
A1 Journal article |
|
Year |
2019 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
|
|
Volume |
58 |
Issue |
10 |
Pages |
6669-6683 |
|
|
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
|
Abstract |
Quasi phase-pure (>98 wt %) MAX phase solid solution ceramics with the (ZryTi)(2)(Al-0.5,Sn-0.5)C stoichiometry and variable Zr/Ti ratios were synthesized by both reactive hot pressing and pressureless sintering of ZrH2, TiH2, Al, Sn, and C powder mixtures. The influence of the different processing parameters, such as applied pressure and sintering atmosphere, on phase purity and microstructure of the produced ceramics was investigated. The addition of Sn to the (Zr,Ti)(2)AlC system was the key to achieve phase purity. Its effect on the crystal structure of a 211-type MAX phase was assessed by calculating the distortions of the octahedral M6C and trigonal M(6)A prisms due to steric effects. The M(6)A prismatic distortion values were found to be smaller in Sn-containing double solid solutions than in the (Zr,Ti)(2)AlC MAX phases. The coefficients of thermal expansion along the < a > and < c > directions were measured by means of Rietveld refinement of high-temperature synchrotron X-ray diffraction data of (Zr1-x,Ti-x)(2)(Al-0.5,Sn-0.5)C MAX phase solid solutions with x = 0, 0.3, 0.7, and 1. The thermal expansion coefficient data of the Ti-2(Al-0.5,Sn-0.5)C solid solution were compared with those of the Ti2AlC and Ti2SnC ternary compounds. The thermal expansion anisotropy increased in the (Zr,Ti)(2)(Al-0.5,Sn-0.5)C double solid solution MAX phases as compared to the Zr-2(Al-0.5,Sn-0.5)C and Ti-2(Al-0.5,Sn-0.5)C end-members. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000469304700014 |
Publication Date |
2019-05-01 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0020-1669 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
4.857 |
Times cited |
3 |
Open Access |
Not_Open_Access |
|
|
Notes |
; H. Roussel and D. Pinek are acknowledged for the Ti<INF>2</INF>SnC single-crystal production and high-temperature XRD measurements performed at Grenoble INP-LMGP-CMTC. This research was funded partly by the European Atomic Energy Community's (Euratom) Seventh Framework Programme FP7/2007-2013 under Grant Agreement No. 604862 (FP7MatISSE), and partly by the Euratom research and training programme 2014-2018 under Grant Agreement No. 740415 (H2020 IL TROVATORE). T.L. thanks the Agency for Innovation by Science and Technology (IWT), Flanders, Belgium, for Ph.D. Grant No. 131081. B.T. acknowledges the financial support of the SCK.CEN Academy for Nuclear Science and Technology. All authors gratefully acknowledge Synchrotron SOLEIL for the allocated time at the DIFFABS beamline in association with Project 20161410 entitled “Investigation of (Zr-Ti)-Al-C MAX phases with in-situ high-temperature XRD” and the Hercules Foundation for Project AKUL/1319 (CombiS(T)EM). ; |
Approved |
Most recent IF: 4.857 |
|
|
Call Number |
UA @ admin @ c:irua:160318 |
Serial |
5261 |
|
Permanent link to this record |
|
|
|
|
Author ![sorted by Author field, ascending order (up)](img/sort_asc.gif) |
Tunca, B.; Lapauw, T.; Karakulina, O.M.; Batuk, M.; Cabioc’h, T.; Hadermann, J.; Delville, R.; Lambrinou, K.; Vleugels, J. |
![goto web page url](http://nano.uantwerpen.be/nanorefs/img/www.gif)
![find record details (via OpenURL) openurl](img/xref.gif)
|
|
Title |
Synthesis of MAX Phases in the Zr-Ti-Al-C System |
Type |
A1 Journal article |
|
Year |
2017 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
|
|
Volume |
56 |
Issue |
56 |
Pages |
3489-3498 |
|
|
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
|
Abstract |
This study reports on the synthesis and characterization of MAX phases in the (Zr,Ti)n+1AlCn system. The MAX phases were synthesized by reactive hot pressing and pressureless sintering in the 1350–1700 °C temperature range. The produced ceramics contained large fractions of 211 and 312 (n = 1, 2) MAX phases, while strong evidence of a 413 (n = 3) stacking was found. Moreover, (Zr,Ti)C, ZrAl2, ZrAl3, and Zr2Al3 were present as secondary phases. In general, the lattice parameters of the hexagonal 211 and 312 phases followed Vegard’s law over the complete Zr-Ti solid solution range, but the 312 phase showed a non-negligible deviation from Vegard’s law around the (Zr0.33,Ti0.67)3Al1.2C1.6 stoichiometry. High-resolution scanning transmission electron microscopy combined with X-ray diffraction demonstrated ordering of the Zr and Ti atoms in the 312 phase, whereby Zr atoms occupied preferentially the central position in the close-packed M6X octahedral layers. The same ordering was also observed in 413 stackings present within the 312 phase. The decomposition of the secondary (Zr,Ti)C phase was attributed to the miscibility gap in the ZrC-TiC system. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000397171100045 |
Publication Date |
2017-03-20 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0020-1669 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
4.857 |
Times cited |
26 |
Open Access |
OpenAccess |
|
|
Notes |
Fonds Wetenschappelijk Onderzoek, G.0431.10N.F ; Agentschap voor Innovatie door Wetenschap en Technologie, 131081 ; European Atomic Energy Community, 604862 ; SCK-CEN Academy for Nuclear Science and Technology; Hercules Foundation, Project/Award no: AKUL/1319 Project/Award no: ZW09-09 ; |
Approved |
Most recent IF: 4.857 |
|
|
Call Number |
EMAT @ emat @ c:irua:141794 |
Serial |
4491 |
|
Permanent link to this record |
|
|
|
|
Author ![sorted by Author field, ascending order (up)](img/sort_asc.gif) |
Vernimmen, J.; Meynen, V.; Herregods, S.J.F.; Mertens, M.; Lebedev, O.I.; Van Tendeloo, G.; Cool, P. |
![goto web page (via DOI) doi](http://nano.uantwerpen.be/nanorefs/img/doi.gif)
|
|
Title |
New insights in the formation of combined zeolitic/mesoporous materials by using a one-pot templating synthesis |
Type |
A1 Journal article |
|
Year |
2011 |
Publication |
European journal of inorganic chemistry |
Abbreviated Journal |
Eur J Inorg Chem |
|
|
Volume |
|
Issue |
27 |
Pages |
4234-4240 |
|
|
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Laboratory of adsorption and catalysis (LADCA) |
|
|
Abstract |
Zeolitic growth is often absent or occurs in separate phases when synthetic strategies based on the combination of zeolite templates and mesopore templating agents are applied. In this work, zeolitic growth and mesopore formation have been investigated at different temperatures by applying a one-pot templating approach, based on a TS-1 zeolite synthesis whereby part of the microtemplate (tetrapropylammonium hydroxide, TPAOH) is replaced by a mesotemplate (hexadecyltrimethylammonium bromide, CTMABr). Moreover, the synthesis duration and the molar ratio of the microtemplate/mesotemplate have also been studied. The different syntheses clearly show the inherent competitive mechanism between zeolitic growth and mesopore formation. These insights have led to the conclusion that by following a one-pot templating strategy with standard, nonexotic commercial templates, i.e. CTMABr and TPAOH, it is not possible to develop a true hierarchical mesoporous zeolite, meaning a mesoporous siliceous material with highly crystalline zeolitic walls. The resultant materials are instead combined zeolitic/mesoporous composite structures with, however, highly tuneable and controllable porosity characteristics. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
Weinheim |
Editor |
|
|
|
Language |
|
Wos |
000296143500014 |
Publication Date |
2011-08-17 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
1434-1948; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
2.444 |
Times cited |
7 |
Open Access |
|
|
|
Notes |
Fwo |
Approved |
Most recent IF: 2.444; 2011 IF: 3.049 |
|
|
Call Number |
UA @ lucian @ c:irua:91574 |
Serial |
2315 |
|
Permanent link to this record |
|
|
|
|
Author ![sorted by Author field, ascending order (up)](img/sort_asc.gif) |
Wang, C.; Xin, X.; Shu, M.; Huang, S.; Zhang, Y.; Li, X. |
![goto web page (via DOI) doi](http://nano.uantwerpen.be/nanorefs/img/doi.gif)
|
|
Title |
Scalable synthesis of one-dimensional Na2Li2Ti6O14 nanofibers as ultrahigh rate capability anodes for lithium-ion batteries |
Type |
A1 Journal article |
|
Year |
2019 |
Publication |
Inorganic Chemistry Frontiers |
Abbreviated Journal |
Inorg Chem Front |
|
|
Volume |
6 |
Issue |
3 |
Pages |
646-653 |
|
|
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
|
Abstract |
Carbon anode materials for Li-ion batteries have been operated close to their theoretical rate and cycle limits. Therefore, titanium-based materials have attracted great attention due to their high stability. Here, Na2Li2Ti6O14 nanofibers as anode materials were prepared through a controlled electrospinning method. The Na2Li2Ti6O14 nanofibers presented superior electrochemical performance with high rate capability and long cycle life and can be regarded as a competitive anode candidate for advanced Li-ion batteries. One-dimensional (1D) Na2Li2Ti6O14 nanofibers are able to deliver a capacity of 128.5 mA h g(-1) at 0.5C, and demonstrate superior high-rate charge-discharge capability and cycling stability (the reversible charge capacity is 77.8 mA h g(-1) with a capacity retention of 99.45% at the rate of 10C after 800 cycles). The 1D structure is considered to contribute remarkably to increased rate capability and stability. This simple and scalable method indicates that the Na2Li2Ti6O14 nanofibers have a practical application potential for high performance lithium-ion batteries. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000461092500027 |
Publication Date |
2018-11-17 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
2052-1553 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
4.036 |
Times cited |
3 |
Open Access |
Not_Open_Access |
|
|
Notes |
; The authors acknowledge financial support from the National Natural Science Foundation of China (21571110), Natural Science Foundation of Zhejiang Province (LY18B010003), and the Ningbo Key Innovation Team (2014B81005), and sponsorship by the K.C. Wong Magna Fund in Ningbo University. ; |
Approved |
Most recent IF: 4.036 |
|
|
Call Number |
UA @ admin @ c:irua:158566 |
Serial |
5258 |
|
Permanent link to this record |
|
|
|
|
Author ![sorted by Author field, ascending order (up)](img/sort_asc.gif) |
Weber, D.; Huber, M.; Gorelik, T.E.; Abakumov, A.M.; Becker, N.; Niehaus, O.; Schwickert, C.; Culver, S.P.; Boysen, H.; Senyshyn, A.; Poettgen, R.; Dronskowski, R.; Ressler, T.; Kolb, U.; Lerch, M. |
![goto web page (via DOI) doi](http://nano.uantwerpen.be/nanorefs/img/doi.gif)
|
|
Title |
Molybdenum oxide nitrides of the Mo2(O,N,\square)5 type : on the way to Mo2O5 |
Type |
A1 Journal article |
|
Year |
2017 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
|
|
Volume |
56 |
Issue |
15 |
Pages |
8782-8792 |
|
|
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
|
Abstract |
Blue-colored molybdenum oxide nitrides of the Mo-2(O,N,square)(5) type were synthesized by direct nitridation of commercially available molybdenum trioxide with a mixture of gaseous ammonia and oxygen. Chemical composition, crystal structure, and stability of the obtained and hitherto unknown compounds are studied extensively. The average oxidation state of +5 for molybdenum is proven by Mo K near-edge X-ray absorption spectroscopy; the magnetic behavior is in agreement with compounds exhibiting (MoO6)-O-v units. The new materials are stable up to similar to 773 K in an inert gas atmosphere. At higher temperatures, decomposition is observed. X-ray and neutron powder diffraction, electron diffraction, and high-resolution transmission electron microscopy reveal the structure to be related to VNb9O24.9-type phases, however, with severe disorder hampering full structure determination. Still, the results demonstrate the possibility of a future synthesis of the potential binary oxide Mo2O5. On the basis of these findings, a tentative suggestion on the crystal structure of the potential compound Mo2O5, backed by electronic-structure and phonon calculations from first principles, is given. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
Easton, Pa |
Editor |
|
|
|
Language |
|
Wos |
000407405500026 |
Publication Date |
2017-07-17 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0020-1669 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
4.857 |
Times cited |
3 |
Open Access |
Not_Open_Access |
|
|
Notes |
; Financial support from the Deutsche Forschungsgemeinschaft (SPP 1415, LE 781/ 11-1, DR 342/22-2) is gratefully acknowledged. The authors are grateful to J. Barthel, Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons Julich, Germany, for STEM image simulations. This work was further supported by Diamond Light Source (beamtime awards EE13560) within beamtime proposal SP13560. The Hamburg Synchrotron Radiation Laboratory, HASYLAB, and the FRM II, Garching, are acknowledged for providing beamtime. ; |
Approved |
Most recent IF: 4.857 |
|
|
Call Number |
UA @ lucian @ c:irua:145727 |
Serial |
4744 |
|
Permanent link to this record |
|
|
|
|
Author ![sorted by Author field, ascending order (up)](img/sort_asc.gif) |
Weill, F.; Chevalier, B.; Chambon, M.; Tressaud, A.; Darriet, B.; Etourneau, J.; Van Tendeloo, G. |
|
|
Title |
Electron microscopy investigation of superconducting La2Cu(O,F)4+y oxyfluoride |
Type |
A1 Journal article |
|
Year |
1993 |
Publication |
European journal of solid state and inorganic chemistry |
Abbreviated Journal |
|
|
|
Volume |
30 |
Issue |
|
Pages |
1095-1108 |
|
|
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
|
Abstract |
|
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
Paris |
Editor |
|
|
|
Language |
|
Wos |
A1993MX13500006 |
Publication Date |
0000-00-00 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0992-4361 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
|
Times cited |
2 |
Open Access |
|
|
|
Notes |
|
Approved |
no |
|
|
Call Number |
UA @ lucian @ c:irua:7505 |
Serial |
955 |
|
Permanent link to this record |
|
|
|
|
Author ![sorted by Author field, ascending order (up)](img/sort_asc.gif) |
Weill; Chevalier; Chambon; Tressaud; Darriet; Etourneau; Van Tendeloo, G. |
|
|
Title |
Electron-microscopy investigation of superconducting la2cu(o, f)4+y oxyfluoride |
Type |
A1 Journal article |
|
Year |
1993 |
Publication |
European journal of solid state and inorganic chemistry |
Abbreviated Journal |
|
|
|
Volume |
30 |
Issue |
11 |
Pages |
1095-1108 |
|
|
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
|
Abstract |
The fluorination of La2CuO4 can lead to different oxyfluoride compounds depending on the TF2 temperature of the fluorine gas treatment. When 150-degrees-C T(F2) less-than-or-equal-to 200-degrees-c less-than-or-equal-to 200-degrees-C a superconducting material is obtained. Previous neutron diffraction experiments as well as the EXAFS measurements at the La L(III) edge indicate that extra anions lie in an interstitial site between the two (LaO) layers. Electron diffraction patterns clearly show the existence of an incommensurate modulation due to the presence of shear planes. A second phase is also pointed out which can be obtained as a major component when the fluorination temperature is raised to 230-degrees-C. This phase which is not a superconductor crystallizes with the monoclinic symmetry. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
Paris |
Editor |
|
|
|
Language |
|
Wos |
A1993MX13500006 |
Publication Date |
0000-00-00 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0992-4361 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
|
Times cited |
2 |
Open Access |
|
|
|
Notes |
|
Approved |
no |
|
|
Call Number |
UA @ lucian @ c:irua:95476 |
Serial |
954 |
|
Permanent link to this record |
|
|
|
|
Author ![sorted by Author field, ascending order (up)](img/sort_asc.gif) |
Xu, X.; Jones, M.A.; Cassidy, S.J.; Manuel, P.; Orlandi, F.; Batuk, M.; Hadermann, J.; Clarke, S.J. |
![goto web page url](http://nano.uantwerpen.be/nanorefs/img/www.gif)
![find record details (via OpenURL) openurl](img/xref.gif)
|
|
Title |
Magnetic Ordering in the Layered Cr(II) Oxide Arsenides Sr2CrO2Cr2As2and Ba2CrO2Cr2As2 |
Type |
A1 Journal article |
|
Year |
2020 |
Publication |
Inorganic Chemistry |
Abbreviated Journal |
Inorg Chem |
|
|
Volume |
59 |
Issue |
21 |
Pages |
15898-15912 |
|
|
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
|
Abstract |
Sr2CrO2Cr2As2 and Ba2CrO2Cr2As2 with Cr2+ ions in CrO2 sheets and in CrAs layers crystallize with the Sr2Mn3Sb2O2 structure (space group I4/mmm, Z = 2) and lattice parameters a = 4.00800(2) Å, c = 18.8214(1) Å (Sr2CrO2Cr2As2) and a = 4.05506(2) Å, c = 20.5637(1) Å (Ba2CrO2Cr2As2) at room temperature. Powder neutron diffraction reveals checkerboard-type antiferromagnetic ordering of the Cr2+ ions in the arsenide layers below TN1Sr, of 600(10) K (Sr2CrO2Cr2As2) and TN1Ba 465(5) K (Ba2CrO2Cr2As2) with the moments initially directed perpendicular to the layers in both compounds. Checkerboard-type antiferromagnetic ordering of the Cr2+ ions in the oxide layer below 230(5) K for Ba2CrO2Cr2As2 occurs with these moments also perpendicular to the layers, consistent with the orientation preferences of d4 moments in the two layers. In contrast, below 330(5) K in Sr2CrO2Cr2As2, the oxide layer Cr2+ moments are initially oriented in the CrO2 plane; but on further cooling, these moments rotate to become perpendicular to the CrO2 planes, while the moments in the arsenide layers rotate by 90° with the moments on the two sublattices remaining orthogonal throughout [behavior recently reported independently by Liu et al. [Liu et al. Phys. Rev. B 2018, 98, 134416]]. In Sr2CrO2Cr2As2, electron diffraction and high resolution powder X-ray diffraction data show no evidence for a structural distortion that would allow the two Cr2+ sublattices to couple, but high resolution neutron powder diffraction data suggest a small incommensurability between the magnetic structure and the crystal structure, which may account for the coupling of the two sublattices and the observed spin reorientation. The saturation values of the Cr2+ moments in the CrO2 layers (3.34(1) μB (for Sr2CrO2Cr2As2) and 3.30(1) μB (for Ba2CrO2Cr2As2)) are larger than those in the CrAs layers (2.68(1) μB for Sr2CrO2Cr2As2 and 2.298(8) μB for Ba2CrO2Cr2As2) reflecting greater covalency in the arsenide layers. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
|
Editor |
|
|
|
Language |
|
Wos |
000588738100035 |
Publication Date |
2020-11-02 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0020-1669 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
4.6 |
Times cited |
|
Open Access |
OpenAccess |
|
|
Notes |
We thank the UK EPSRC (EP/M020517/1 and EP/P018874/ 1) and the Leverhulme Trust (RPG-2014-221) for funding and the ISIS pulsed neutron and muon source (RB1610357 and RB1700075) and the Diamond Light Source Ltd. (EE13284 and EE18786) for the award of beam time. We thank Dr. A. Baker and Dr. C. Murray for support on I11. |
Approved |
Most recent IF: 4.6; 2020 IF: 4.857 |
|
|
Call Number |
EMAT @ emat @c:irua:176058 |
Serial |
6704 |
|
Permanent link to this record |
|
|
|
|
Author ![sorted by Author field, ascending order (up)](img/sort_asc.gif) |
Zhang, H.; Yang, J.-H.; Shpanchenko, R.V.; Abakumov, A.M.; Hadermann, J.; Clérac, R.; Dikarev, E.V. |
![find record details (via OpenURL) openurl](img/xref.gif)
|
|
Title |
New class of single-source precursors for the synthesis of main group-transition metal oxides: heterobimetallic Pb-Mn \beta-diketonates |
Type |
A1 Journal article |
|
Year |
2009 |
Publication |
Inorganic chemistry |
Abbreviated Journal |
Inorg Chem |
|
|
Volume |
48 |
Issue |
17 |
Pages |
8480-8488 |
|
|
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
|
|
Abstract |
Heterometallic lead−manganese â-diketonates have been isolated in pure form by several synthetic methods that include solid-state and solution techniques. Two compounds with different Pb/Mn ratios, PbMn2(hfac)6 (1) and PbMn(hfac)4 (2) (hfac = hexafluoroacetylacetonate), can be obtained in quantitative yield by using different starting materials. Single crystal X-ray investigation revealed that the solid-state structure of 1 contains trinuclear molecules in which lead metal center is sandwiched between two [Mn(hfac)3] units, while 2 consists of infinite chains of alternating [Pb(hfac)2] and [Mn(hfac)2] fragments. The heterometallic structures are held together by strong Lewis acid−base interactions between metal atoms and diketonate ligands acting in chelating-bridging fashion. Spectroscopic investigation confirmed the retention of heterometallic structures in solutions of non-coordinating solvents as well as upon sublimation-deposition procedure. Thermal decomposition of heterometallic diketonates has been systematically investigated in a wide range of temperatures and annealing times. For the first time, it has been shown that thermal decomposition of heterometallic diketonates results in mixed-metal oxides, while both the structure of precursors and the thermolysis conditions have a significant influence on the nature of the resulting oxides. Five different Pb−Mn oxides have been detected by X-ray powder diffraction when studying the decomposition of 1 and 2 in the temperature range 500−800 °C. The phase that has been previously reported as Pb0.43MnO2.18 was synthesized in the pure form by decomposition of 1, and crystallographically characterized. The orthorhombic unit cell parameters of this oxide, obtained by electron diffraction technique, have been subsequently refined using X-ray powder diffraction data. Besides that, a previously unknown lead−manganese oxide has been obtained at low temperature decomposition and short annealing times. The parameters of its monoclinically distorted unit cell have been determined. The EDX analysis revealed that this compound has a Pb/Mn ratio close to 1:4 and contains no appreciable amount of fluorine. |
|
|
Address |
|
|
|
Corporate Author |
|
Thesis |
|
|
|
Publisher |
|
Place of Publication |
Easton, Pa |
Editor |
|
|
|
Language |
|
Wos |
000269313500056 |
Publication Date |
2009-08-04 |
|
|
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
|
Series Volume |
|
Series Issue |
|
Edition |
|
|
|
ISSN |
0020-1669;1520-510X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
4.857 |
Times cited |
28 |
Open Access |
|
|
|
Notes |
|
Approved |
Most recent IF: 4.857; 2009 IF: 4.657 |
|
|
Call Number |
UA @ lucian @ c:irua:78486 |
Serial |
2308 |
|
Permanent link to this record |