L1 0 FePt thin films with high coercivity and fine grain by rapid thermal annealing with high heating ramp rate

Abstract

Iron–platinum (FePt) thin films are deposited on an oxidized Si (100) substrates followed by a rapid thermal annealing (RTA) process with various heating rates from 20 °C/s to 100 °C/s. It is found that the coercivity of the FePt films increases and the grain size decreases as the heating rate of RTA increases. As the as-deposited FePt films are annealed at 700 °C with a high heating ramp rate of 100 °C/s, the grain size of FePt films is determined to be as small as 14 nm, and its in-plane coercivity and perpendicular coercivity reached as high as 11.1 and 9.5 kOe, respectively. On the other hand, the isolated magnetic domains are observed by magnetic force microscope (MFM) at a high heating ramp rate of 100 °C/s.