TY - JOUR
T1 - Effect of A -site size difference on polar behavior in M BiScNbO 6 (M=Na, K, and Rb)
T2 - Density functional calculations
AU - Takagi, Shigeyuki
AU - Subedi, Alaska
AU - Cooper, Valentino R.
AU - Singh, David J.
PY - 2010/10/11
Y1 - 2010/10/11
N2 - We investigate the effect of A -site size differences in the double perovskites BiScO3-M NbO3 (M=Na, K, and Rb) using first-principles calculations. We find that the polarization of these materials is 70-90 μC/cm2 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.
AB - We investigate the effect of A -site size differences in the double perovskites BiScO3-M NbO3 (M=Na, K, and Rb) using first-principles calculations. We find that the polarization of these materials is 70-90 μC/cm2 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.
UR - http://www.scopus.com/inward/record.url?scp=78049365467&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.82.134108
DO - 10.1103/PhysRevB.82.134108
M3 - Article
AN - SCOPUS:78049365467
SN - 1098-0121
VL - 82
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
IS - 13
M1 - 134108
ER -