Effect of Substrate Temperature on Growth and Magnetic Properties of Nanocrystal Fe3N Thin Films

The nanocrystal epsilon-Fe3N thin films were deposited on Si(100) substrate at different substrate temperatures of 150, 250, 350, 450 degrees C by DC magnetron sputtering. The structure, morphology and magnetic properties of the films deposited at different substrate temperature were characterized via X-ray diffraction (XRD), scanning electron microscopy(SEM) and vibrating sample magnetometer(VSM). The results,show that epsilon-Fe3N has ferromagnetic properties, and its grain sizes, growth velocity and unsaturated magnetization measured at 400 kA/m field increase with increasing substrate temperature. The coercive force H, increased to 18.72 kA/m at substrate temperature of 350 degrees C firstly, the H-c decreased with the substrate temperature increasing to 450 degrees C. It can be deduced that exchange length (L-ex) of nanocrystal epsilon-Fe3N thin films was about grain size 30 nm.