Quantum Mechanical Study of YTiO3 to the Investigation of Piezoelectricity

Raimundo Dirceu De Paula Ferreira,Oswaldo Treu-Filho,Marcio De Souza Farias,José Ciríaco Pinheiro,Marcos Antonio Barros Dos Santos,Rogério Toshiaki Kondo,Jardel Pinto Barbosa,Antonio Florêncio De Figueiredo,Maycon Da Silva Lobato

doi:10.1155/2011/123492

Abstract

In previous articles we reported through theoretical studies the piezoelectric effect in BaTiO3, SmTiO3, and YFeO3. In this paper, we used the Douglas-Kroll-Hess (DKH) second-order scalar relativistic method to investigate the piezoelectricity in YTiO3. In the calculations we used the [6s4p] and [10s5p4d] Gaussian basis sets for the O (3P) and Ti (5S) atoms, respectively, from the literature in combination with the (30s21p16d)/[15s9p6d] basis set for the Y (3D) atom, obtained by generator coordinate Hartree-Fock (GCHF) method, and they had their quality evaluated using calculations of total energy and orbital energies (HOMO and HOMO-1) of the 2TiO+1 and 1YO+1 fragments. The dipole moment, the total energy, and the total atomic charges in YTiO3 in Cs space group were calculated. When we analyze those properties we verify that it is reasonable to believe that YTiO3 does not present piezoelectric properties.

Highlights

Even today barium titanate (BaTiO3), the first perovskite structure developed, is widely used in the industry
The polymorphic forms of BaTiO3 have been likened by Kay and Vousden [1] to a displacement of the central Ti+4 ion within its oxygen octahedron towards one, two, and three of the six adjacent oxygen ions as the temperature is lowered
By the generator coordinate Hartree-Fock (GCHF) approach, we choose the one-electron as the continuous superposition

Summary

Introduction

Even today barium titanate (BaTiO3), the first perovskite structure developed, is widely used in the industry. The polymorphic forms of BaTiO3 have been likened by Kay and Vousden [1] to a displacement of the central Ti+4 ion within its oxygen octahedron towards one, two, and three of the six adjacent oxygen ions as the temperature is lowered. This is a simplification of the actual atomic displacements, but it is a useful first approximation for understanding the structure. For a review about the role of the perovskite structure in ceramic science and technology see Bhalla et al [4]

Objectives

Methods

Results