First-principles investigation of the ferroelectric, piezoelectric and nonlinear optical properties of LiNbO(3)-type ZnTiO(3)

The newly synthesized LN-type ZnTiO(3) (J. Am. Chem. Soc. 2014, 136, 2748) contains cations with the electronic configurations nd(10) (Zn(2+): 3d(10)) along with second-order Jahn-Teller (SOJT) nd(0) (Ti(4+): 3d(0)) cations. This is different from traditional ferroelectrics with the electric configurations of d(0) transition metal ions or/and lone pair electrons of ns(2). 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 LiNbO(3)-type ZnTiO(3). 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/cm(2). The Raman scattering peaks of A(1) and E modes are assigned to their zone-center optical modes. Additionally, the large piezoelectric and nonlinear optical susceptibilities reveal that LiNbO(3)-type ZnTiO(3) is a high-performance lead-free piezoelectric and nonlinear optical crystal.