Investigation of electronic structure and optical properties for tetragonal CeAlO3 under pressure

The electronic structure of tetragonal CeAlO3 is investigated under different pressures by use of the method of Heyd-Scuseria-Ernzerhof screened hybrid functional. The same downward trend is observed for both the lattice constants and the band gap as the pressure increases. The variations of some optical properties such as epsilon ( omega ) , R ( omega ) and L ( omega ) with pressure are investigated in detail. The results show that epsilon(1) ( 0 ) increases continuously with the increasing pressure, and the same trend for main peak of epsilon(2) ( omega ) is obviously obtained. In addition, prominent peaks of R ( omega ) and L ( omega ) have distinct blue-shift with the increase of the pressure.