Electronic structure and lattice dynamics of orthorhombic BiGaO3

The electronic structure, structural, elastic and vibrational properties of the orthorhombic BiGaO3 were calculated by using the density functional theory. For the electronic structure calculations standard generalized gradient approximation, nonlocal hybrid Heyd-Scuseria-Emzerhof and semilocal Tran-Blaha functionals were used. The standard and hybrid functionals were applied to obtain structural parameters. The electronic structure shows that BiGaO3 is a indirect band gap semiconductor. The values of the band gap are 1.88 eV, 3.14 eV and 3.00 eV within generalized gradient approximation, hybrid and semilocal functionals, respectively. The direct method have been used to obtain the vibrational properties. The phonon band structure shows a soft mode between Gamma and Z direction. This soft mode could be responsible for structural phase transition. (C) 2014 Elsevier B.V. All rights reserved.