Magnetization reversal modes and coercive field dependence on perpendicular magnetic anisotropy in FePt thin films

Abstract

The competition between shape and perpendicular magnetic anisotropies in magnetic thin films gives rise to unusual magnetic behaviors. In ferromagnetic thin films, the presence of an out-of-plane component of the magnetic anisotropy may induce a transition from planar to stripe-like magnetic domains above a critical thickness, tc. In this article, we present a detailed study of the magnetization switching mechanism in FePt thin films, where this phenomenon is observed. Using micromagnetic simulations and experiments, we found that below tc the reversal mechanism is well described by the two-phase model while above this thickness the magnetization within each stripe reverses by coherent rotation. We also analyzed the out-of-plane component of the magnetic anisotropy and its temperature dependence, probing that substrate-induced strains are responsible for the abnormal coercive field behavior observed for FePt films with t>tc.

Thermal evolution of low-temperature magnetic texture modulation in fept thin films by direct visualization

“…Associated with the microstructure [26], this dependency was pointed as an indication of the change in the magnetic texture [23]. More recently, it was better described as the result of the substrateinduced strains [27]. By differentiating M Msat with respect to H ( ∆M ∆H ), a measure of the associated rate of change is obtained [28].…”

Atomic level mechanism of disorder-order transformation kinetics at nanoscale in FePt based systems

“…FePt thin films are widely investigated by researchers for their possible applications in the recording media industry and random memory applications. Owing to the high magneto crystalline anisotropy associated with the L1 0 ordered phase, it is believed to be a potential candidate for such applications [1][2][3][4][5]. L1 0 ordered FePt has a face centered tetragonal (FCT) structure with alternative layers of Fe and Pt atoms along the c-axis in the unit cell.…”