Lowering Of L1_0 Phase Transition Temperature Of Fept Thin Films By Single Shot H~+ Ion Exposure Using Plasma Focus Device

摘要

FePt thin films are exposed to pulsed energetic H~+ ion beam from plasma focus. In irradiated films, the phase transition from the low K_u disordered face-centered-cubic structure to high K_u ordered face-centered-tetragonal phase was achieved at 400 ℃ with the order parameter S ranging from 0.73 to 0.83, high coercivity of about 5356 kA/m, high negative nucleation field of about 7700 kA/m and high squareness ratio ranging from 0.73 to 0.79. The advantage of using plasma focus device is that it can lower phase transition temperature and significantly enhance the magnetic properties by a pulsed single shot exposure.