Nonmagnetic impurities induced magnetism in SnO2

A density functional study is performed to investigate the magnetism induced by the nonmagnetic impurity substitution for the cation in SnO2. The calculated results show that the K impurity substitution leads to a robust magnetism in SnO2, and the induced magnetic moments are mainly attributed to the first shell of oxygen atoms surrounding the impurity atom. Meanwhile, no magnetism is observed in SnO2 doped with Ca which implies a decreasing tendency of induced magnetic moments for Sn substituted by vacancy, K, and Ca. It is also demonstrated that the magnetic coupling constant oscillates as a function of K–K separation distance, and the Curie temperature above room temperature can be obtained in K-doped SnO2.