Enhanced structural and magnetic ordering of FePt/TiOx bilayers by ion-beam deposition and annealing

摘要

The effect of annealing temperature on the microstructure and magnetic properties of FePt/TiOx bilayers was systemically studied. The grain sizes decreased and the surface roughness increased as the annealing temperatures increased; at the meanwhile, the interface between the FePt and TiOx layer became more graded, indicating there were more interdiffusion processes as the annealing temperature increased. The coercivity increased as the annealing temperature was raised, indicating more face center tetragonal-phase FePt was formed with higher annealing temperatures. Coercivities over 11 kOe were acquired in both in-plane and out-of-plane directions after annealing at 650 °C for 10 min. TiOx -capped FePt samples tended to possess higher coercivities after annealing at higher temperatures, which is favorable for high areal density recording applications.