First-principles investigation of the ferroelectric, piezoelectric and nonlinear optical properties of LiNbO3-type ZnTiO3

Abstract

The newly synthesized LN-type ZnTiO3 (J. Am. Chem. Soc. 2014, 136, 2748) contains cations with the electronic configurations nd10 (Zn2+: 3d10) along with second-order Jahn-Teller (SOJT) nd0 (Ti4+: 3d0) cations. This is different from traditional ferroelectrics with the electric configurations of d0 transition metal ions or/and lone pair electrons of ns2. Using a first-principles approach based on density functional theory, we investigate the electronic structure, zone-center phonon modes, piezoelectric and nonlinear optical properties of the LiNbO3-type ZnTiO3. The electronic structure indicates that this compound is a wide direct-band-gap insulator. The results reveal that this compound is a good ferroelectric material with a large spontaneous polarization of 90.43μC/cm2. The Raman scattering peaks of A1 and E modes are assigned to their zone-center optical modes. Additionally, the large piezoelectric and nonlinear optical susceptibilities reveal that LiNbO3-type ZnTiO3 is a high-performance lead-free piezoelectric and nonlinear optical crystal.