First-principle investigation on electronic structures and magnetic properties of EuNbO₃ phases

Recently, structure phase transitions were experimentally found in europium niobate (EuNbO3). Here, we present a density-functional theory (DFT) investigation of structural, electronic and magnetic properties of the experimentally observed three phases of EuNbO3: orthorhombic (space group Imma), tetragonal (I4/mcm) and cubic (Pmm). The calculated structural parameters and magnetic properties of the ground state are in agreement with available experimental results. The ground states of the orthorhombic and cubic phases are ferromagnetic metals and the tetragonal phase is predicted as an antiferromagnetic metal. Besides, the Eu atom has the magnetic moment of 6.9 μB/atom in the EuNbO3 phases. The present study provides a theoretical approach to understand EuNbO3 in its different phases.