Effect of AlN Film on the Magnetic Properties of Rare Earth-Transition Metal Film

The amorphous TbFeCo films covered with the protective AIN films have been prepared by the rf magnetron sputtering system. It is found that the protective AIN films not only protect rare earth elements from oxidation and enhance magneto-optical Kerr effect but also affect the magnetic properties of the rare earth-transition metal films. The coercivity H_c and perpendicular magnetic anisotropy energy constants K'_U1 and K_U2 of the films are changed with the thickness of the protective AIN films. It can be explained according to the stress mechanism and the model of single ion anisotropy.