Vanadium Clustering/Declustering in P2-Na1/2VO2 Layered Oxide

被引：24

作者：

Guignard, Marie ^{[1
]}

Carlier, Dany ^{[1
]}

Didier, Christophe ^{[1
]}

Suchomel, Matthew R. ^{[2
]}

Elkaim, Erik ^{[3
]}

Bordet, Pierre ^{[4
]}

Decourt, Rodolphe ^{[1
]}

Darriet, Jacques ^{[1
]}

Delmas, Claude ^{[1
]}

机构：

[1] Univ Bordeaux, ICMCB, CNRS, F-33608 Pessac, France

[2] Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA

[3] Synchrotron SOLEIL, F-91192 Gif Sur Yvette, France

[4] UJF, Inst NEEL, CNRS, F-38042 Grenoble, France

来源：

CHEMISTRY OF MATERIALS | 2014年 / 26卷 / 04期

关键词：

SOLID-STATE NMR; INSULATOR TRANSITION; PHASE-TRANSITIONS; CRYSTAL-STRUCTURE; METAL; SUPERSTRUCTURE; DIFFRACTION; ELECTRONS;

D O I：

10.1021/cm403114k

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

The new layered phase P2-Na1/2VO2 has been synthesized by sodium electrochemical deintercalation. Its structure has been studied by high resolution powder diffraction, pair distribution function analysis, and nuclear magnetic resonance spectroscopy between 300 and 350 K. An increase of 2 orders of magnitude in its electronic conductivity has been observed at approximately 322 K, and a structural transition has been found to occur simultaneously. The arrangement of sodium ordering in P2-Na1/2VO2, which maximizes sodium-sodium distances to lower electrostatic repulsions between alkali ions, is found to be unchanged across this transition. At room temperature, high resolution powder diffraction and pair distribution function analysis reveal the triangular lattice formed by vanadium ions to be distorted by the formation of pseudotrimers clusters with vanadium-vanadium distances as short as 2.581 angstrom. Above the transition, the pseudotrimers disappear and the triangular vanadium lattice becomes more regular with a mean vanadium-vanadium distance of similar to 2.88 angstrom. At 350 K, the increase in P2-Na1/2VO2 electronic conductivity is due to enhanced charge transport resulting from the declustering of vanadium ions. These results highlight how sodium ordering between the MO2 layers and the electronic transport within the MO2 layers are intimately correlated in NaxMO2-type sodium-layered oxides.

引用

页码：1538 / 1548

页数：11

共 40 条

[31] New Insights into the Crystal and Electronic Structures of Li1+xV1-xO2 from Solid State NMR, Pair Distribution Function Analyses, and First Principles Calculations [J].