Structural and magnetic properties of Cu-alloyed FePd films

Multilayer films [Cu(d Å)/Fe(9 Å)/Pd(11 Å)]5 were deposited at room temperature on Si(001)/SiO2(400 nm) substrates. In order to induce chemical L10 ordering, the as-deposited samples were post-annealed by rapid thermal annealing (RTA) at 600 °C for 90 s followed additionally by heating in ultra-high vacuum (UHV) at 700 °C up to several hours. In this study the impact of post-annealing on the structural and magnetic properties of FePdCu alloy films in dependence on the Cu content was investigated. It was found that the addition of Cu to the FePd alloy has a strong influence on the chemical ordering process and the (001) texture formation. After the RTA treatment only an isotropic distribution of the easy axis of magnetization with coercive fields in the range of a few hundred mT was observed. In contrast, samples which were additionally heated for 1 h at 700 °C revealed an out-of-plane easy axis of magnetization with an effective magnetic anisotropy of about 2×105 J/m3 for the sample containing 10 at% of Cu.