Effect of $A$-site size difference on polar behavior in $M$BiScNbO$_6$,($M$$=$Na, K and Rb): Density functional calculations

S. Takagi; A. Subedi; V. R. Cooper; D. J. Singh

doi:10.1103/PhysRevB.82.134108

Effect of $A$-site size difference on polar behavior in $M$BiScNbO$_6$,($M$$=$Na, K and Rb): Density functional calculations

Materials Science 2010-11-24 v1

Authors: S. Takagi , A. Subedi , V. R. Cooper , D. J. Singh

View on arXiv ↗ PDF ↗ DOI ↗

Abstract

We investigate the effect of $A$ -site size differences in the double perovskites BiScO $_3$ - $M$ NbO $_3$ ( $M$ $=$ Na, K and Rb) using first-principles calculations. We find that the polarization of these materials is 70 $\sim$ 90 $\mu$ C/cm $^2$ along the rhombohedral direction. The main contribution to the high polarization comes from large off-centerings of Bi ions, which are strongly enhanced by the suppression of octahedral tilts as the $M$ ion size increases. A high Born effective charge of Nb also contributes to the polarization and this contribution is also enhanced by increasing the $M$ ion size.

Keywords

density functional calculations double perovskites polarization Bi off-centering octahedral tilts Born effective charge

Cite

@article{arxiv.1008.2782,
  title  = {Effect of $A$-site size difference on polar behavior in $M$BiScNbO$_6$,($M$$=$Na, K and Rb): Density functional calculations},
  author = {S. Takagi and A. Subedi and V. R. Cooper and D. J. Singh},
  journal= {arXiv preprint arXiv:1008.2782},
  year   = {2010}
}

Related papers

View all related →