Effect of the interplay between layering sequence permutations and thickness on the magnetic features of Fe/Ni/Gd hetero-films

Abstract

The effect of the interplay between layering sequence permutations and film thickness on the temperature-dependent magnetization and spin structure of Fe/Ni/Gd hetero-films (sizes: 10 nm × 10 nm × d nm and 20 nm × 20 nm × d nm, where d is the film thickness and with all possible layer sequence permutations) is investigated in the framework of an atomistic spin dynamics formalism. As the main conclusion of our work, for d = 2 and 4 nm, layering sequence permutations do not affect the evolution of the mean temperature-dependent magnetization of hetero-films. Nonetheless, dramatic magnetic modulations appear for d = 6 nm. More specifically, a Gd film sandwiched between Fe and Ni films (FeGdNi hetero-film) exhibits a depressed mean temperature-dependent magnetization in the temperature range of 150 K to 700 K. In contrast, both FeNiGd and NiFeGd hetero-films show a more or less similar magnetization evolution.