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

Abstract

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.

References in corpus (4)

• First-principles study of spontaneous polarization in multiferroic BiFeO${}_3$
• Lattice Dynamics in PMN
• Frustration of tilts and A-site driven ferroelectricity in KNbO_3-LiNbO_3 alloys
• Low-temperature phases in Pb(Zr0.52Ti0.48)O3: A neutron powder diffraction study

Cited by in corpus (3)

• Effect of $A$-site size difference on polar behavior in $M$BiScNbO${}_6$,($M$$=$Na, K and Rb): Density functional calculations
• Negative thermal expansion near the precipice of structural stability in open perovskites
• New class of planar ferroelectric Mott insulators via first principles design