Magnetic and structural properties of high coercivity Sm(Co, Ni, Cu) sputtered thin films

The effects of heat treatments on the structural and magnetic properties of Sm(Co, Ni, Cu) sputtered thin films were investigated. Crystallization of the initially amorphous magnetic films produces a huge enhancement of coercivity (from 100 Oe to more than 40 kOe). The crystallized structure consists of exchange coupled precipitates in the nanometers range. The pinning of the magnetization reversal at the high anisotropy grains is proposed as the origin of such a magnetic behavior. By tuning the coercivity through the annealing conditions, these systems could be used in a number of applications, from longitudinal recording media to thin film permanent magnet. (C) 1998 American Institute of Physics. [S0021-8979(98)46411-9].