Amorphous GdFeCo Films Exhibiting Large and Tunable Perpendicular Magnetic Anisotropy

TL;DR

This study investigates amorphous GdFeCo films, revealing their composition-dependent magnetic compensation and large, tunable perpendicular magnetic anisotropy, suitable for nanoscale magnetic devices.

Contribution

It provides new insights into the compositional and temperature dependence of magnetic properties in amorphous GdFeCo films, expanding the range for designing tunable PMA materials.

Findings

Low Gd content (20-34 at.%) exhibits magnetic compensation and large PMA.

High Gd content (52-59 at.%) shows no compensation but retains large PMA.

Room temperature films achieve low magnetization with coercivity up to ~6.6 kOe.

Abstract

We report the compositional and temperature dependence of magnetic compensation in amorphous GdFeCo films. Magnetic compensation is attributed to the competition between antiferromagnetic coupling of rare-earth with transition-metal (TM) ions and ferromagnetic interaction between the TM ions. The low-Gd region from 20 to 34 at. % was found to exhibit compensation phenomena characterized by a low saturation magnetization and perpendicular magnetic anisotropy (PMA) near the compensation temperature. Compensation temperature was not observed in previously unreported high-Gd region from 52 to 59 at. %, in qualitative agreement with results from recent model calculations. However, low magnetization was achieved at room temperature, accompanied by a large PMA with coercivity reaching ~6.6 kOe. The observed perpendicular magnetic anisotropy of amorphous GdFeCo films probably has a structural origin consistent with certain aspects of the atomic-scale anisotropy. Our findings have broadened the composition range of transition metal-rare earth alloys for designing PMA films, making it attractive for tunable magnetic anisotropy in nanoscale devices.