B-cation effect on the electronic and magnetic properties of CeBO3 (B=Ga, In) compounds from first principles study

The ab initio APW+lo method is used to study the cation effect on the electronic structure of CeBO3 (B=Ga, In) compounds. High-pressure structural behavior, magnetic phase stabilities and electronic properties of both materials have been investigated. The observed most stable phases are the orthorhombic (Pnma) and hexagonal (P63cm) for CeGaO3 and CeInO3, respectively. It is shown that the ferromagnetic (FM) state in CeGaO3 is energetically more favorable than the anti-ferromagnetic (AFM) one, unlike CeInO3 where the AFM-III configuration is the lowest in energy. LSDA+U calculation shows that the valence band maximum is located at T point and the conduction band minimum is located at the center of the Brillouin zone, resulting in a wide indirect energy band gap of about 3.6 eV in the ferromagnetic ordering CeGaO3 which is typical of semiconductor with large gap. CeInO3 compound keeps the metallic character using DFT+U calculation.