Fe₅₀Pt_50–xPd_x alloy thin films with L1₀ structure epitaxially grown on MgO(001) substrates

¹ Faculty of Science and Engineering, Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan
² Graduate School of Fine Arts, Tokyo University of the Arts, 12-8 Ueno-koen, Taito-ku, Tokyo 110-8714, Japan

^a Corresponding author: futamoto@elect.chuo-u.ac.jp

Published online: 3 July 2014

Abstract

Fe₅₀Pt_50–xPd_x (at. %, x = 0, 12.5, 25, 37.5, 50) alloy epitaxial films are prepared on MgO(001) substrates at temperatures ranging from room temperature to 600 °C by radio-frequency magnetron sputtering. The effects of substrate temperature and Pd/Pt composition on the order degree, c-axis distribution, and magnetic property are investigated. With increasing the substrate temperature, L1₀ ordering is enhanced for all the compositions. The order degree of film deposited at 600 °C decreases from 0.37 to 0.23 as the x value increases from 0 to 12.5 at. %. With further increasing the x value, the order degree increases up to 0.69. The Fe₅₀Pt_50–xPd_x films with x ≥ 25 consist of only an L1₀(001) single-crystal with the c-axis perpendicular to the substrate surface, whereas the films with x < 25 involve two types of L1₀(100) variant with the c-axis lying in the film plane in addition to L1₀(001) variant. The c-axis distribution is influenced by the Pd/Pt composition. The magnetic anisotropy is reflecting the c-axis distribution and the order degree.