Electronic structure and lattice dynamics of rhombohedral BiAlO3 from first-principles

The structural, elastic, electronic, dynamical (zone-center phonon modes and Born effective charge tensors), and ferroelectric properties of the rhombohedral BiAlO3 were calculated within various exchange-correlation functionals. The standard local-density (LDA) and generalized gradient (GGA) approximations, and nonlocal hybrid Heyd-Scuseria-Ernzerhof (HSE) were used. We have also performed the electronic structure calculations with meta-GGA Tran-Blaha functional. BiAlO3 is indirect band gap semiconductor with the value of band gap: 2.87 eV (GGA), 4.14 eV (HSE), and 3.78 eV (TB-mBJ). The calculated spontaneous polarization is 81 μC/cm2 (87 μC/cm2) for GGA (HSE). The vibrational spectrum including LO-TO splitting was calculated within GGA. The zone-center phonon modes with LO-TO splitting for BiAlO3 were compared with those in isostructural BiFeO3.