Possible Ferroelectricity in SnTiO3 by First-Principles Calculations

The prospect of lattice structure and ferroelectricity of SnTiO 3 have been studied by first-principles calculations within local density approximation. The results showed that the SnTiO 3 has the minimum total energy within almost tetragonal perovskite structure of a=b =3.80 A, c =4.09 A. The calculated electronic structure of SnTiO 3 resembles that of PbTiO 3 because the Ti 3d states, Sn 5 s and 5 p states hybridize with the O 2 p orbitals. The moment of spontaneous polarization of SnTiO 3 was estimated as 73 μ C/cm 2 , which is as large as that of PbTiO 3 .