Comparison of band profiles and magnetic properties of the different phases of BaTbO3

The full potential linearized augmented plane wave (FP-LAPW) method within the frame work of the density functional theory is used to study BaTbO3 in three different phases; cubic (space group pm-3m), tetragonal (I4/mcm) and orthorhombic (Ibmm). The calculated structural parameters and geometries are found in agreement with the experimental results. The spin polarized electronic band structures and densities of states for all the three phases demonstrate that BaTbO3 is insulator. The insulating nature of the material is consistent with the experiments and contradicts with the theoretical results of the metallic behavior and narrow band gap semiconductor. Furthermore, the calculated magnetic moment of Tb4+ is in close agreement with the experiments. This comprehensive theoretical study provides a realistic theoretical approach to understand BaTbO3 in its different phases.