First-principles study of electronic structure and magnetic properties of Cu-doped CeO_2

摘要

48%We performed first-principles calculations within density-functional theory to study the origin of the magnetism in Cu-doped CeO_2. We show that the electron spin-polarization and the magnetic coupling are sensitive to the defect structures in Cu-doped CeO_2. The substitution of a Cu atom for a Ce atom (Cu_(Ce)) induces a local magnetic moment of 3.00 μb around per impurity, but the magnetic coupling between local magnetic moments is very weak. The defect complex consisting of a Cu_(Ce) and a nearest-neighbor oxygen vacancy (V_o) has low formation energy and thus high plausibility in Cu-doped CeO_2. Although the local magnetic moment triggered by the Cu_(Ce)-V_o complex is only 1.00 μb per complex, strong ferromagnetic coupling between the defect complexes is achieved which can be attributed to a magnetic coupling chain formed by the strong p-d interaction between Cu and host O atoms.