Predicting New Iron Garnet Thin Films with Perpendicular Magnetic Anisotropy

TL;DR

This paper predicts 20 new iron garnet thin film/substrate pairs with stable perpendicular magnetic anisotropy at room temperature, aiding the development of advanced spintronic devices.

Contribution

It introduces a predictive model for identifying new garnet film/substrate combinations exhibiting stable PMA at room temperature, expanding material options for spintronics.

Findings

20 new substrate/garnet pairs with stable PMA predicted

Effective anisotropy energies calculated for 10 garnet films

Guidelines for fabricating low-damping garnet films provided

Abstract

Perpendicular magnetic anisotropy (PMA) is a necessary condition for many spintronic applications like spin-orbit torques switching, logic and memory devices. An important class of magnetic insulators with low Gilbert damping at room temperature are iron garnets, which only have a few PMA types such as terbium and samarium iron garnet. More and stable PMA garnet options are necessary for researchers to be able to investigate new spintronic phenomena. In this study, we predict 20 new substrate/magnetic iron garnet film pairs with stable PMA at room temperature. The effective anisotropy energies of 10 different garnet films that are lattice-matched to 5 different commercially available garnet substrates have been calculated using shape, magnetoelastic and magnetocrystalline anisotropy terms. Strain type, tensile or compressive depending on substrate choice, as well as the sign and the magnitude of the magnetostriction constants of garnets determine if a garnet film may possess PMA. We show the conditions in which Samarium, Gadolinium, Terbium, Holmium, Dysprosium and Thulium garnets may possess PMA on the investigated garnet substrate types. Guidelines for obtaining garnet films with low damping are presented. New PMA garnet films with tunable saturation moment and field may improve spin-orbit torque memory and compensated magnonic thin film devices.