Improving atomic ordering in iron platinum magnetic film by suppressing grain growth by rapid thermal annealing with a high heating ramp rate

In this study the structural and magnetic properties of FePt thin film processed at different annealing temperatures were studied. The FePt thin films were deposited by direct current (dc) magnetron sputtering on Si/SiO2 (110) wafer at a room temperature. The films were then annealed at temperature range of 575-675 °C for 20s with a rapid thermal annealing (RTA) process at a high heating ramp rate of 100 K/s. The structural, magnetic and surface properties of samples were studied by X-ray diffraction (XRD), scanning electron microscopy and vibrating sample magnetometer. XRD results showed that the ordered structure of FePt phase is formed at 600 °C. The grain size of thin films was increased with an increase in annealing temperature. The uniform thickness was achieved for the whole series of samples. The maximum out-of-plane coercivity reached to 1.7 MA/m for sample annealed at 650 °C. Magnetic interaction which was evaluated by Henkel plots reflects the existence of exchange interaction in thin films.