Phase transformation and negative thermal expansion in TaVO5

Wang, Xiaowei and Huang, Qingzhen and Deng, Jinxia and Yu, Ranbo and Chen, Jun and Xing, Xianran (2011) Phase transformation and negative thermal expansion in TaVO5. Inorganic Chemistry, 50 (6). pp. 2685-2690. ISSN 0020-1669

Abstract

Two phase transformations of TaVO5 were observed by DSC and/or dilatometry measurements in the studied temperature range. X-ray diffraction and neutron powder diffraction structure refinements indicated a phase transformation at-14 °C from a monoclinic symmetry with space group P2 1/c to an orthorhombic symmetry with space group Pnma above this temperature. The rigid TaO6 octahedron in orthorhombic phase becomes nonregular at-14 °C, which results in the transition from Pnma to P2 1/c. TaVO5 was found to be a negative thermal expansion material above room temperature. The calculated volumetric thermal expansion coefficients (TECs) are-8.92 × 10-6 °C-1 in the range of 20-600 °C, and-2.19 × 10-5 °C-1 above 600 °C, respectively. The negative thermal expansion behavior is accounted for by the tilt of the TaO6 and VO4 polyhedra, where the shrinkage of the VO4 tetrahedra result in the increase of Ta-O-V angles on heating, while the angle of Ta-O1-Ta maintains at 180° in the framework.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Files associated with this item cannot be displayed due to copyright restrictions.
Faculty / Department / School: No Faculty
Date Deposited: 14 Jun 2017 01:27
Last Modified: 14 Jun 2017 01:27
Fields of Research : 03 Chemical Sciences > 0302 Inorganic Chemistry > 030201 Bioinorganic Chemistry
Socio-Economic Objective: E Expanding Knowledge > 97 Expanding Knowledge > 970103 Expanding Knowledge in the Chemical Sciences
Identification Number or DOI: 10.1021/ic200003n
URI: http://eprints.usq.edu.au/id/eprint/31990

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