The role of spontaneous polarization in the negative thermal expansion of tetragonal PbTiO3-based compounds

Chen, Jun and Nittala, Krishna and Forrester, Jennifer S. and Jones, Jacob L. and Deng, Jinxia and Yu, Ranbo and Xing, Xianran (2011) The role of spontaneous polarization in the negative thermal expansion of tetragonal PbTiO3-based compounds. Journal of the American Chemical Society, 133 (29). pp. 11114-11117. ISSN 0002-7863

Abstract

PbTiO3-based compounds are well-known ferroelectrics that exhibit a negative thermal expansion more or less in the tetragonal phase. The mechanism of negative thermal expansion has been studied by high-temperature neutron powder diffraction performed on two representative compounds, 0.7PbTiO3 - 0.3BiFeO3 and 0.7PbTiO3 - 0.3Bi(Zn1/2Ti1/2)O3, whose negative thermal expansion is contrarily enhanced and weakened, respectively. With increasing temperature up to the Curie temperature, the spontaneous polarization displacement of Pb/Bi (|zPb/Bi) is weakened in 0.7PbTiO3 - 0.3BiFeO3 but well-maintained in 0.7PbTiO3 - 0.3Bi(Zn1/2Ti1/2)O3. There is an apparent correlation between tetragonality (c/a) and spontaneous polarization. Direct experimental evidence indicates that the spontaneous polarization originating from Pb/Bi - O hybridization is strongly associated with the negative thermal expansion. This mechanism can be used as a guide for the future design of negative thermal expansion of phase-transforming oxides.


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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 04:07
Last Modified: 14 Jun 2017 04:07
Uncontrolled Keywords: Experimental evidence; Future designs; High temperature; Negative thermal expansion; Representative compound; Spontaneous polarizations; Tetragonal phase; Tetragonality; General; Zinc and Alloys; Fluid Flow; Electromagnetic Waves in Different Media; Organic Compounds; Materials Science; Clinical and Experimental Biochemistry;
Fields of Research : 03 Chemical Sciences > 0306 Physical Chemistry (incl. Structural) > 030699 Physical Chemistry not elsewhere classified
Socio-Economic Objective: E Expanding Knowledge > 97 Expanding Knowledge > 970103 Expanding Knowledge in the Chemical Sciences
Identification Number or DOI: 10.1021/ja2046292
URI: http://eprints.usq.edu.au/id/eprint/31987

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