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 (C₂¹⁰)BB′ 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(t_2g)-O(2p)-B′(t_2g) Π-binding. Besides including the on site Coulomb interaction, GGA+U calculation is also carried out and the HM property is ensured.