THEORETICAL PREDICTION OF A NEW TYPE OF HALF-METALLIC MATERIALS IN DOUBLE DEROVSKITE Pb2BB′O6 (B, B′ = 3d TRANSITION METAL) VIA FIRST-PRINCIPLE CALCULATIONS

This study investigate the electronic structure of double perovskite Pb2BB′O6 (B, B′ = 3d transition metal atoms) with ab initio calculation. Density functional theory with generalized gradient approximation (GGA) is used to determine the physical proprieties of the materials. Six new half-metallic (HM) materials are found from 45 combinations in double perovskite Pb2BB′O6 (of 3d transition metal atoms). There are five ferromagnetic (FM)-HM materials (Pb2ScCrO6, Pb2ScMnO6, Pb2TiVO6, Pb2TiCrO6 and Pb2CrMnO6) and one ferrimagnetic (FiM)-HM material (Pb2TiFeO6). The HM property of the materials are attributed to the double-exchange interaction mechanism through the B(t2g)-O(2p)-B′(t2g) π-binding. Besides including the on site Coulomb interaction, GGA+U calculation is also carried out and the HM property is ensured.