Records |
Author |
McCalla, E.; Abakumov, A.; Rousse, G.; Reynaud, M.; Sougrati, M.T.; Budic, B.; Mahmoud, A.; Dominko, R.; Van Tendeloo, G.; Hermann, R.P.; Tarascon, J.M.; |
Title |
Novel complex stacking of fully-ordered transition metal layers in Li4FeSbO6 materials |
Type |
A1 Journal article |
Year |
2015 |
Publication |
Chemistry of materials |
Abbreviated Journal |
Chem Mater |
Volume |
27 |
Issue |
27 |
Pages |
1699-1708 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
As part of a broad project to explore Li4MM'O-6 materials (with M and M' being selected from a wide variety of metals) as positive electrode materials for Li-ion batteries, the structures of Li4FeSbO6 materials with both stoichiometric and slightly deficient lithium contents are studied here. For lithium content varying from 3.8 to 4.0, the color changes from yellow to black and extra superstructure peaks are seen in the XRD patterns. These extra peaks appear as satellites around the four superstructure peaks affected by the stacking of the transition metal atoms. Refinements of both XRD and neutron scattering patterns show a nearly perfect ordering of Li, Fe, and Sb in the transition metal layers of all samples, although these refinements must take the stacking faults into account in order to extract information about the structure of the TM layers. The structure of the most lithium rich sample, where the satellite superstructure peaks are seen, was determined with the help of HRTEM, XRD, and neutron scattering. The satellites arise due to a new stacking sequence where not all transition metal layers are identical but instead two slightly different compositions stack in an AABB sequence giving a unit cell that is four times larger than normal for such monoclinic layered materials. The more lithium deficient samples are found to contain metal site vacancies based on elemental analysis and Mossbauer spectroscopy results. The significant changes in physical properties are attributed to the presence of these vacancies. This study illustrates the great importance of carefully determining the final compositions in these materials, as very small differences in compositions may have large impacts on structures and properties. |
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 |
|
Wos |
000350919000032 |
Publication Date |
2015-02-12 |
Series Editor |
|
Series Title |
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Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0897-4756;1520-5002; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
9.466 |
Times cited |
22 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 9.466; 2015 IF: 8.354 |
Call Number ![sorted by Call Number field, ascending order (up)](img/sort_asc.gif) |
c:irua:125469 |
Serial |
2373 |
Permanent link to this record |
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|
|
Author |
Struzzi, C.; Erbahar, D.; Scardamaglia, M.; Amati, M.; Gregoratti, L.; Lagos; Van Tendeloo, G.; Snyders, R.; Ewels, C.; Bittencourt, C. |
Title |
Selective decoration of isolated carbon nanotubes by potassium evaporation : scanning photoemission microscopy and density functional theory |
Type |
A1 Journal article |
Year |
2015 |
Publication |
Journal of materials chemistry C : materials for optical and electronic devices |
Abbreviated Journal |
J Mater Chem C |
Volume |
3 |
Issue |
3 |
Pages |
2518-2527 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Site selective doping of aligned carbon nanostructures represents a promising approach for their implementation in actual devices. In the present work we report on alkali metals decoration on low density vertically aligned carbon nanotubes, disclosing the possibility of engineering site selective depositions of potassium atoms on the carbon systems. Photoemission measurements were combined with microscopy demonstrating the effective spatial control of alkali deposition. The changes of electronic structures of locally doped carbon regions were studied by exploiting the ability of the scanning photoemission microscopy technique. From the analysis of experimental data supported by theoretical calculations, we show the tuning of the charge transfer from potassium to carbon atoms belonging to neighboring nanotubes or along the same tube structure. |
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 |
|
Wos |
000350984200011 |
Publication Date |
2014-12-30 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2050-7526;2050-7534; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
5.256 |
Times cited |
6 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 5.256; 2015 IF: 4.696 |
Call Number ![sorted by Call Number field, ascending order (up)](img/sort_asc.gif) |
c:irua:125496 |
Serial |
2963 |
Permanent link to this record |
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|
|
Author |
McCalla, E.; Sougrati, M.T.; Rousse, G.; Berg, E.J.; Abakumov, A.; Recham, N.; Ramesha, K.; Sathiya, M.; Dominko, R.; Van Tendeloo, G.; Novák, P.; Tarascon, J.M.; |
Title |
Understanding the roles of anionic redox and oxygen release during electrochemical cycling of lithium-rich layered Li4FeSbO6 |
Type |
A1 Journal article |
Year |
2015 |
Publication |
Journal of the American Chemical Society |
Abbreviated Journal |
J Am Chem Soc |
Volume |
137 |
Issue |
137 |
Pages |
4804-4814 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Li-rich oxides continue to be of immense interest as potential next generation Li-ion battery positive electrodes, and yet the role of oxygen during cycling is still poorly understood. Here, the complex electrochemical behavior of Li4FeSbO6 materials is studied thoroughly with a variety of methods. Herein, we show that oxygen release occurs at a distinct voltage plateau from the peroxo/superoxo formation making this material ideal for revealing new aspects of oxygen redox processes in Li-rich oxides. Moreover, we directly demonstrate the limited reversibility of the oxygenated species (O-2(n-); n = 1, 2, 3) for the first time. We also find that during charge to 4.2 V iron is oxidized from +3 to an unusual +4 state with the concomitant formation of oxygenated species. Upon further charge to 5.0 V, an oxygen release process associated with the reduction of iron +4 to +3 is present, indicative of the reductive coupling mechanism between oxygen and metals previously reported. Thus, in full state of charge, lithium removal is fully compensated by oxygen only, as the iron and antimony are both very close to their pristine states. Besides, this charging step results in complex phase transformations that are ultimately destructive to the crystallinity of the material. Such findings again demonstrate the vital importance of fully understanding the behavior of oxygen in such systems. The consequences of these new aspects of the electrochemical behavior of lithium-rich oxides are discussed in detail. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
Language |
|
Wos |
000353177100036 |
Publication Date |
2015-03-26 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0002-7863;1520-5126; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
13.858 |
Times cited |
86 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 13.858; 2015 IF: 12.113 |
Call Number ![sorted by Call Number field, ascending order (up)](img/sort_asc.gif) |
c:irua:126019 |
Serial |
3805 |
Permanent link to this record |
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|
|
Author |
McCalla, E.; Prakash, A.S.; Berg, E.; Saubanere, M.; Abakumov, A.M.; Foix, D.; Klobes, B.; Sougrati, M.T.; Rousse, G.; Lepoivre, F.; Mariyappan, S.; Doublet, M.L.; Gonbeau, D.; Novak, P.; Van Tendeloo, G.; Hermann, R.P.; Tarascon, J.M.; |
Title |
Reversible Li-intercalation through oxygen reactivity in Li-rich Li-Fe-Te oxide materials |
Type |
A1 Journal article |
Year |
2015 |
Publication |
Journal of the electrochemical society |
Abbreviated Journal |
J Electrochem Soc |
Volume |
162 |
Issue |
162 |
Pages |
A1341-A1351 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
Lithium-rich oxides are a promising class of positive electrode materials for next generation lithium-ion batteries, and oxygen plays a prominent role during electrochemical cycling either by forming peroxo-like species and/or by irreversibly forming oxygen gas during first charge. Here, we present Li-Fe-Te-O materials which show a tremendous amount of oxygen gas release. This oxygen release accounts for nearly all the capacity during the first charge and results in vacancies as seen by transmission electron microscopy. There is no oxidation of either metal during charge but significant changes in their environments. These changes are particularly extreme for tellurium. XRD and neutron powder diffraction both show limited Changes during cycling and no appreciable change in lattice parameters. A density functional theory study of this material is performed and demonstrates that the holes created on some of the oxygen atoms upon oxidation are partially stabilized through the formation of shorter O-O bonds, i.e. (O-2)(n-) species which on further delithiation show a spontaneous O-2 de-coordination from the cationic network and migration to the now empty lithium layer. The rate limiting step during charge is undoubtedly the diffusion of oxygen either out along the lithium layer or via columns of oxygen atoms. (C) 2015 The Electrochemical Society. All rights reserved. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
New York, N.Y. |
Editor |
|
Language |
|
Wos |
000355643700030 |
Publication Date |
2015-04-29 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0013-4651;1945-7111; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.259 |
Times cited |
23 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 3.259; 2015 IF: 3.266 |
Call Number ![sorted by Call Number field, ascending order (up)](img/sort_asc.gif) |
c:irua:126445 |
Serial |
2903 |
Permanent link to this record |
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|
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Author |
Frolov, A.S.; Sanchez-Barriga, J.; Callaert, C.; Hadermann, J.; Fedorov, A., V; Usachov, D.Y.; Chaika, A.N.; Walls, B.C.; Zhussupbekov, K.; Shvets, I., V.; Muntwiler, M.; Amati, M.; Gregoratti, L.; Varykhalov, A.Y.; Rader, O.; Yashina, L., V. |
Title |
Atomic and electronic structure of a multidomain GeTe crystal |
Type |
A1 Journal article |
Year |
2020 |
Publication |
Acs Nano |
Abbreviated Journal |
Acs Nano |
Volume |
14 |
Issue |
12 |
Pages |
16576-16589 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Renewed interest in the ferroelectric semi-conductor germanium telluride was recently triggered by the direct observation of a giant Rashba effect and a 30-year-old dream about a functional spin field-effect transistor. In this respect, all-electrical control of the spin texture in this material in combination with ferroelectric properties at the nanoscale would create advanced functionalities in spintronics and data information processing. Here, we investigate the atomic and electronic properties of GeTe bulk single crystals and their (111) surfaces. We succeeded in growing crystals possessing solely inversion domains of similar to 10 nm thickness parallel to each other. Using HAADF-TEM we observe two types of domain boundaries, one of them being similar in structure to the van der Waals gap in layered materials. This structure is responsible for the formation of surface domains with preferential Te-termination (similar to 68%) as we determined using photoelectron diffraction and XPS. The lateral dimensions of the surface domains are in the range of similar to 10-100 nm, and both Ge- and Te-terminations reveal no reconstruction. Using spin-ARPES we establish an intrinsic quantitative relationship between the spin polarization of pure bulk states and the relative contribution of different terminations, a result that is consistent with a reversal of the spin texture of the bulk Rashba bands for opposite configurations of the ferroelectric polarization within individual nanodomains. Our findings are important for potential applications of ferroelectric Rashba semiconductors in nonvolatile spintronic devices with advanced memory and computing capabilities at the nanoscale. |
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 |
000603308800022 |
Publication Date |
2020-11-02 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1936-0851 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
17.1 |
Times cited |
|
Open Access |
OpenAccess |
Notes |
|
Approved |
Most recent IF: 17.1; 2020 IF: 13.942 |
Call Number ![sorted by Call Number field, ascending order (up)](img/sort_asc.gif) |
UA @ admin @ c:irua:175027 |
Serial |
6716 |
Permanent link to this record |
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|
|
Author |
Frolov, A.S.; Callaert, C.; Batuk, M.; Hadermann, J.; Volykhov, A.A.; Sirotina, A.P.; Amati, M.; Gregoratti, L.; Yashina, L.V. |
Title |
Nanoscale phase separation in the oxide layer at GeTe (111) surfaces |
Type |
A1 Journal article |
Year |
2022 |
Publication |
Nanoscale |
Abbreviated Journal |
Nanoscale |
Volume |
14 |
Issue |
35 |
Pages |
12918-12927 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
As a semiconductor ferroelectric, GeTe has become a focus of renewed attention due to the recent discovery of giant Rashba splitting. It already has a wide range of applications, from thermoelectricity to data storage. Its stability in ambient air, as well as the structure and properties of an oxide layer, define the processing media for device production and operation. Here, we studied a reaction between the GeTe (111) surface and molecular oxygen for crystals having solely inversion domains. We evaluated the reaction kinetics both ex situ and in situ using NAP XPS. The structure of the oxide layer is extensively discussed, where, according to HAADF-STEM and STEM-EDX, nanoscale phase separation of GeO2 and Te is observed, which is unusual for semiconductors. We believe that such behaviour is closely related to the ferroelectric properties and the domain structure of GeTe. |
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 |
|
Wos |
000847743300001 |
Publication Date |
2022-08-25 |
Series Editor |
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Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2040-3364; 2040-3372 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
Impact Factor |
6.7 |
Times cited |
|
Open Access |
Not_Open_Access |
Notes |
|
Approved |
Most recent IF: 6.7 |
Call Number ![sorted by Call Number field, ascending order (up)](img/sort_asc.gif) |
UA @ admin @ c:irua:190665 |
Serial |
7181 |
Permanent link to this record |
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|
Author |
Ati, M.; Sathiya, M.; Boulineau, S.; Reynaud, M.; Abakumov, A.; Rousse, G.; Melot, B.; Van Tendeloo, G.; Tarascon, J.-M. |
Title |
Understanding and promoting the rapid preparation of the triplite-phase of LiFeSO4F for use as a large-potential Fe cathode |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Journal of the American Chemical Society |
Abbreviated Journal |
J Am Chem Soc |
Volume |
134 |
Issue |
44 |
Pages |
18380-18387 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The development of new electrode materials, which are composed of Earth-abundant elements and that can be made via eco-efficient processes, is becoming absolutely necessary for reasons of sustainable production. The 3.9 V triplite-phase of LiFeSO4F, compared to the 3.6 V tavorite-phase, could satisfy this requirement provided the currently complex synthetic pathway can be simplified. Here, we present our work aiming at better understanding the reaction mechanism that govern its formation as a way to optimize its preparation. We first demonstrate, using complementary X-ray diffraction and transmission electron microscopy studies, that triplite-LiFeSO4F can nucleate from tavorite-LiFeSO4F via a reconstructive process whose kinetics are significantly influenced by moisture and particle morphology. Perhaps the most spectacular finding is that it is possible to prepare electrochemically active triplite-LiFeSO4F from anhydrous precursors using either reactive spark plasma sintering (SPS) synthesis in a mere 20 min at 320 degrees C or room temperature ball milling for 3 h. These new pathways appear to be strongly driven by the easy formation of a disordered phase with higher entropy, as both techniques trigger disorder via rapid annealing steps or defect creation. Although a huge number of phases adopts the tavorite structure-type, this new finding offers both a potential way to prepare new compositions in the triplite structure and a wealth of opportunities for the synthesis of new materials which could benefit many domains beyond energy storage. |
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 |
000310720900041 |
Publication Date |
2012-10-12 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0002-7863;1520-5126; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
13.858 |
Times cited |
36 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 13.858; 2012 IF: 10.677 |
Call Number ![sorted by Call Number field, ascending order (up)](img/sort_asc.gif) |
UA @ lucian @ c:irua:105147 |
Serial |
3802 |
Permanent link to this record |
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|
|
Author |
Subban, C.V.; Ati, M.; Rousse, G.; Abakumov, A.M.; Van Tendeloo, G.; Janot, R.; Tarascon, J.-M. |
Title |
Preparation, structure, and electrochemistry of layered polyanionic hydroxysulfates : LiMSO4OH (M = Fe, Co, Mn) electrodes for Li-Ion batteries |
Type |
A1 Journal article |
Year |
2013 |
Publication |
Journal of the American Chemical Society |
Abbreviated Journal |
J Am Chem Soc |
Volume |
135 |
Issue |
9 |
Pages |
3653-3661 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
The Li-ion rechargeable battery, due to its high energy density, has driven remarkable advances in portable electronics. Moving toward more sustainable electrodes could make this technology even more attractive to large-volume applications. We present here a new family of 3d-metal hydroxysulfates of general formula LiMSO4OH (M = Fe, Co, and Mn) among which (i) LiFeSO4OH reversibly releases 0.7 Li+ at an average potential of 3.6 V vs Li+/Li-0, slightly higher than the potential of currently lauded LiFePO4 (3.45 V) electrode material, and (ii) LiCoSO4OH shows a redox activity at 4.7 V vs Li+/Li-0. Besides, these compounds can be easily made at temperatures near 200 degrees C via a synthesis process that enlists a new intermediate phase of composition M-3(SO4)(2)(OH)(2) (M = Fe, Co, Mn, and Ni), related to the mineral caminite. Structurally, we found that LiFeSO4OH is a layered phase unlike the previously reported 3.2 V tavorite LiFeSO4OH. This work should provide an impetus to experimentalists for designing better electrolytes to fully tap the capacity of high-voltage Co-based hydroxysulfates, and to theorists for providing a means to predict the electrochemical redox activity of two polymorphs. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
Language |
|
Wos |
000315936700056 |
Publication Date |
2013-02-01 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0002-7863;1520-5126; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
13.858 |
Times cited |
53 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 13.858; 2013 IF: 11.444 |
Call Number ![sorted by Call Number field, ascending order (up)](img/sort_asc.gif) |
UA @ lucian @ c:irua:108283 |
Serial |
2708 |
Permanent link to this record |
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|
|
Author |
Reynaud, M.; Rousse, G.; Abakumov, A.M.; Sougrati, M.T.; Van Tendeloo, G.; Chotard, J.-N.; Tarascon, J.-M. |
Title |
Design of new electrode materials for Li-ion and Na-ion batteries from the bloedite mineral Na2Mg(SO4)2\cdot4H2O |
Type |
A1 Journal article |
Year |
2014 |
Publication |
Journal of materials chemistry A : materials for energy and sustainability |
Abbreviated Journal |
J Mater Chem A |
Volume |
2 |
Issue |
8 |
Pages |
2671-2680 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
Mineralogy offers a large database to search for Li- or Na-based compounds having suitable structural features for acting as electrode materials, LiFePO4 being one example. Here we further explore this avenue and report on the electrochemical properties of the bloedite type compounds Na2M(SO4)(2)center dot 4H(2)O (M = Mg, Fe, Co, Ni, Zn) and their dehydrated phases Na2M(SO4)(2) (M = Fe, Co), whose structures have been solved via complementary synchrotron X-ray diffraction, neutron powder diffraction and transmission electron microscopy. Among these compounds, the hydrated and anhydrous iron-based phases show electrochemical activity with the reversible release/uptake of 1 Na+ or 1 Li+ at high voltages of similar to 3.3 V vs. Na+/Na-0 and similar to 3.6 V vs. Li+/Li-0, respectively. Although the reversible capacities remain lower than 100 mA h g(-1), we hope this work will stress further the importance of mineralogy as a source of inspiration for designing eco-efficient electrode materials. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Cambridge |
Editor |
|
Language |
|
Wos |
000331247500031 |
Publication Date |
2013-11-22 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
2050-7488;2050-7496; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
8.867 |
Times cited |
56 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 8.867; 2014 IF: 7.443 |
Call Number ![sorted by Call Number field, ascending order (up)](img/sort_asc.gif) |
UA @ lucian @ c:irua:115807 |
Serial |
659 |
Permanent link to this record |
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|
|
Author |
Sun, M.; Rousse, G.; Abakumov, A.M.; Van Tendeloo, G.; Sougrati, M.-T.; Courty, M.; Doublet, M.-L.; Tarascon, J.-M. |
Title |
An oxysulfate Fe2O(SO4)2 electrode for sustainable Li-based batteries |
Type |
A1 Journal article |
Year |
2014 |
Publication |
Journal of the American Chemical Society |
Abbreviated Journal |
J Am Chem Soc |
Volume |
136 |
Issue |
36 |
Pages |
12658-12666 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
High-performing Fe-based electrodes for Li-based batteries are eagerly pursued because of the abundance and environmental benignity of iron, with especially great interest in polyanionic compounds because of their flexibility in tuning the Fe3+/Fe2+ redox potential. We report herein the synthesis and structure of a new Fe-based oxysulfate phase, Fe2O(SO4)(2), made at low temperature from abundant elements, which electrochemically reacts with nearly 1.6 Li atoms at an average voltage of 3.0 V versus Li+/Li, leading to a sustained reversible capacity of similar to 125 mAh/g. The Li insertiondeinsertion process, the first ever reported in any oxysulfate, entails complex phase transformations associated with the position of iron within the FeO6 octahedra. This finding opens a new path worth exploring in the quest for new positive electrode materials. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
Language |
|
Wos |
000341544600029 |
Publication Date |
2014-08-14 |
Series Editor |
|
Series Title |
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Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0002-7863;1520-5126; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
13.858 |
Times cited |
11 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 13.858; 2014 IF: 12.113 |
Call Number ![sorted by Call Number field, ascending order (up)](img/sort_asc.gif) |
UA @ lucian @ c:irua:119906 |
Serial |
96 |
Permanent link to this record |
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|
|
Author |
Lander, L.; Rousse, G.; Abakumov, A.M.; Sougrati, M.; Van Tendeloo, G.; Tarascon, J.-M. |
Title |
Structural, electrochemical and magnetic properties of a novel KFeSO4F polymorph |
Type |
A1 Journal article |
Year |
2015 |
Publication |
Journal of materials chemistry A : materials for energy and sustainability |
Abbreviated Journal |
J Mater Chem A |
Volume |
3 |
Issue |
3 |
Pages |
19754-19764 |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT) |
Abstract |
In the quest for sustainable and low-cost positive electrode materials for Li-ion batteries, we discovered, as reported herein, a new low temperature polymorph of KFeSO4F. Contrary to the high temperature phase crystallizing in a KTiOPO4-like structure, this new phase adopts a complex layer-like structure built on FeO4F2 octahedra and SO4 tetrahedra, with potassium cations located in between the layers, as solved using neutron and synchrotron diffraction experiments coupled with electron diffraction. The detailed analysis of the structure reveals an alternation of edge-and corner-shared FeO4F2 octahedra leading to a large monoclinic cell of 1771.774(7) angstrom(3). The potassium atoms are mobile within the structure as deduced by ionic conductivity measurements and confirmed by the bond valence energy landscape approach thus enabling a partial electrochemical removal of K+ and uptake of Li+ at an average potential of 3.7 V vs. Li+/Li-0. Finally, neutron diffraction experiments coupled with SQUID measurements reveal a long range antiferromagnetic ordering of the Fe2+ magnetic moments below 22 K with a possible magnetoelectric behavior. |
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Publisher |
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Place of Publication |
Cambridge |
Editor |
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Language |
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Wos |
000362041300018 |
Publication Date |
2015-08-17 |
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 |
2050-7488; 2050-7496 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
8.867 |
Times cited |
11 |
Open Access |
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Notes |
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Approved |
Most recent IF: 8.867; 2015 IF: 7.443 |
Call Number ![sorted by Call Number field, ascending order (up)](img/sort_asc.gif) |
UA @ lucian @ c:irua:132566 |
Serial |
4253 |
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Author |
Bourgeois, J.; Hervieu, M.; Poienar, M.; Abakumov, A.M.; Elkaïm, E.; Sougrati, M.T.; Porcher, F.; Damay, F.; Rouquette, J.; Van Tendeloo, G.; Maignan, A.; Haines, J.; Martin, C.; |
Title |
Evidence of oxygen-dependent modulation in LuFe2O4 |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
Volume |
85 |
Issue |
6 |
Pages |
064102-064120,10 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
Abstract |
A polycrystalline sample of LuFe2O4 has been investigated by means of powder synchrotron x-ray and neutron diffraction and transmission electron microscopy (TEM), along with Mössbauer spectroscopy and transport and magnetic properties. A monoclinic distortion is unambiguously evidenced, and the crystal structure is refined in the monoclinic C2/m space group [aM = 5.9563(1) Å, bM = 3.4372(1) Å, cM = 8.6431(1) Å, β = 103.24(1)°]. Along with the previously reported modulations distinctive of the charge-ordering (CO) of the iron species, a new type of incommensurate order is observed, characterized by a vector q⃗1 = α1a⃗M* + γ1c⃗M* (with α1 ≅ 0.55, γ1 ≅ 0.13). In situ heating TEM observations from 300 to 773 K confirm that the satellites associated with q⃗1 vanish completely, only at a temperature significantly higher than the CO temperature. This incommensurate modulation has a displacive character and corresponds primarily to a transverse displacive modulation wave of the Lu cations position, as revealed by the high resolution, high angle annular dark field scanning TEM images and in agreement with synchrotron data refinements. Analyses of vacuum-annealed samples converge toward the hypothesis of a new ordering mechanism, associated with a tiny oxygen deviation from the O4 stoichiometry. |
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Place of Publication |
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Wos |
000299896900003 |
Publication Date |
2012-02-06 |
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 |
1098-0121;1550-235X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.836 |
Times cited |
24 |
Open Access |
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Notes |
Hercules |
Approved |
Most recent IF: 3.836; 2012 IF: 3.767 |
Call Number ![sorted by Call Number field, ascending order (up)](img/sort_asc.gif) |
UA @ lucian @ c:irua:95042 |
Serial |
1095 |
Permanent link to this record |