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Title: Effect of $$A$$-site size difference on polar behavior in MBiScNbO6, (M=Na, K and Rb): Density functional calculations

Journal Article · · Physical Review B

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.

Research Organization:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Organization:
USDOE Office of Science (SC)
DOE Contract Number:
DE-AC05-00OR22725
OSTI ID:
992544
Journal Information:
Physical Review B, Vol. 82, Issue 13; ISSN 1098-0121
Country of Publication:
United States
Language:
English