Polar behavior of double perovskite (Bi,Pb)ZnNbO6 and (Bi,Sr)ZnNbO6: Density functional calculations

The polar behavior of double perovskite (Bi,Pb)ZnNbO\(_6\) and (Bi,Sr)ZnNbO\(_6\) was investigated using first principles density functional calculations within the local density approximation. These materials have both \(A\)-site size disorder and ions with sterochemical activity. We found a strong...

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Bibliographic Details
Published in:arXiv.org 2010-01
Main Authors: Takagi, S, Subedi, A, Singh, D J, Cooper, V R
Format: Article
Language:English
Subjects:
Density
Ferroelectric materials
Ferroelectricity
First principles
Mathematical analysis
Perovskites
Polarization
Solid solutions
Online Access:Get full text
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Summary:The polar behavior of double perovskite (Bi,Pb)ZnNbO\(_6\) and (Bi,Sr)ZnNbO\(_6\) was investigated using first principles density functional calculations within the local density approximation. These materials have both \(A\)-site size disorder and ions with sterochemical activity. We found a strong ferroelectric distortion in both materials. The polarization of the Pb material is \(>\)80 \(\mu\)C/cm\(^2\) along the rhombohedral direction and the Sr based material is only slightly inferior. The high polarization results mainly from a large off-centering of Bi and the large Born effective charge of Nb, which yields a large contribution polarization although the Nb off-centers by a smaller amount. Neither of these materials favors a tetragonal state, and therefore solid solutions with PbTiO\(_3\) may show morphotoropic phase boundaries.
ISSN:2331-8422
DOI:10.48550/arxiv.1001.2227