Deposition of Crystalline GdIG Samples Using Metal Organic Decomposition Method

Hyeongyu Kim,Jong-Ryul Jeong,Albert M Park,Kab-Jin Kim,Phuoc-Cao Van,Younghun Jo,Hyeonjung Jung,Jung-Woo Yoo,Jiseok Yang

doi:10.3390/magnetochemistry8030028

Abstract

Fabrication of high quality ferrimagnetic insulators is an essential step for ultrafast magnonics, which utilizes antiferromagnetic exchange of the ferrimagnetic materials. In this work, we deposit high-quality GdIG thin films on a (111)-oriented GGG substrate using the Metal Organic Decomposition (MOD) method, a simple and high throughput method for depositing thin film materials. We postannealed samples at various temperatures and examined the effect on structural properties such as crystallinity and surface morphology. We found a transition in the growth mode that radically changes the morphology of the film as a function of annealing temperature and obtained an optimal annealing temperature for a uniform thin film with high crystallinity. Optimized GdIG has a high potential for spin wave applications with a low damping parameter in the order of 10−3, which persists down to cryogenic temperatures.

Highlights

To gadolinium gallium garnet (GGG) (444) peak, a broad peak is observed at 50.3◦, which corresponds to the gadolinium iron garnet (GdIG) (444) peak with a lattice constant of 12.55 Å
We note that the lattice constant of GdIG on GGG is larger than that of a single crystalline GdIG of 12.48 Å due to the pseudo-morphic growth on the GGG substrate [15]
We found that a transition of the growing model of GdIG occurs at around 900 ◦ C above which the film grows with an island pattern

Summary

Introduction

Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. High frequency dynamics from the antiferromagnetic exchange are essential for achieving fast computing spintronic devices [1,2]. To utilize the antiferromagnetic dynamics, a method to overcome its lack of responsiveness to the external field needs to be devised. Compensated ferrimagnet, composed of two antiferromagnetically coupled sublattices [3], enables the fast dynamics of antiferromagnetic materials while having accessibility via external fields similar to ferromagnetic ones

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Conclusion