Magnetically dead layers at sp-impurity-decorated grain boundaries and surfaces in nickel

作者：Vsianska M^*; Sob M

来源：Physical Review B, 2011, 84(1): 014418.

DOI：10.1103/PhysRevB.84.014418

With the help of ab initio electronic structure calculations, we study segregation of the sp elements from the 13th-16th group and the third, fourth, and fifth period of the Periodic Table (i.e., Al, Si, P, S, Ga, Ge, As, Se, In, Sn, Sb, and Te) at the Sigma 5(210) grain boundary (GB) and (210) free surface (FS) in fcc ferromagnetic nickel, and analyze the geometric configuration and the distribution of magnetic moments at the GB and FS without and with impurities. Whereas there is a slight enhancement of magnetization at the clean GB and FS with respect to bulk nickel (3-7% and 24%, respectively), most of these impurities nearly kill or substantially reduce the magnetic moments at the FS and, when segregating interstitially at the GB (i.e., Si, P, S, Ge, As, and Se), they produce magnetically dead layers at the boundary. We demonstrate that the existence of magnetically dead layers is a common phenomenon at the sp-impurity-decorated GB and FS in nickel. It is caused by a strong hybridization of sp states of the impurities with the d states of nickel and a redistribution of electron states in both majority and minority bands.

• 出版日期2011-7-26