First-principles studies on phase stability and electric properties in a polar oxide ZnSnO3

Abstract

First-principles density functional calculations have been performed for a novel polar oxide ZnSnO3 with LiNbO3 (LN) type structure that was synthesized by high-pressure condition. The pressure dependence of the phase stability for Zn2+-Sn4+-O2- ternary system was computed through the calculations of bulk modulus, and we succeeded to reproduce qualitatively the phase transition to LN-type ZnSnO3 phase at high-pressure region. In addition, spontaneous polarizations and Born effective charges for ZnSnO3 was calculated by Berry phase approach, and the obtained results were compared with the electric properties of LiNbO3. The results indicated strong ionic character for Zn2+ and Sn4+ ions, indicating the difference of chemical bonding character and polarization properties between ZnSnO3 and LiNbO3 even with the same crystal structure