Crystal Structure and Magnetic Property of Si3N4/FePd/Si3N4 Thin Films

Si3N4/FePd/Si3N4 trilayer films were prepared by magnetron sputtering. The effect of Si3N4 insert as a non-magnetic material on structure and magnetic properties of FePd films was investigated. The results show that Si3N4 particles distribute between the FePd nanoparticles after heat treatment, which inhibit the growth of FePd grains. Compared with pure FePd films, the grains of Si3N4/FePd /Si3N4 thin films are obviously refined. By adding Si3N4 insert, the crystallographic parameters c/a of FePd films decrease from 0.960 to 0.946, indicating that Si3N4 content could effectively promote the ordering process of FePd films and improve the coercivity and remanence ratio. The coercivity and remanence ratio are increased to 249 kA/m and 0.86, respectively. With the further increase of the annealing time at 600 degrees C, the magnetic property of the Si3N4-doped FePd thin films does not decrease rapidly, and its relatively high magnetic properties maintain over a wide range of annealing time, which indicate that the thermal resistance of FePd thin films are obviously improved. Si3N4 insert plays a great role in promoting the magnetic properties of FePd thin films, which is significant for the development of magnetic recording film materials.