Patterned growth of crystalline Y$_{3}$Fe$_{5}$O$_{12}$ nanostructures with engineered magnetic shape anisotropy

TL;DR

This study demonstrates the patterned growth of epitaxial YIG nanostructures with engineered magnetic anisotropy, enabling precise control of magnetic properties for advanced spintronic applications.

Contribution

It introduces a lithographic patterning method for YIG thin films that achieves controlled magnetic anisotropy and high-quality nanostructures, overcoming previous fabrication challenges.

Findings

YIG nanostructures exhibit narrow FMR linewidth (~4 Oe)

Engineered nanobars show increased coercivity (40 Oe)

Magnetic easy axis aligns with nanobar length, with 195 Oe anisotropy field

Abstract

We demonstrate patterned growth of epitaxial yttrium iron garnet (YIG) thin films using lithographically defined templates on gadolinium gallium garnet (GGG) substrates. The fabricated YIG nanostructures yield the desired crystallographic orientation, excellent surface morphology, and narrow ferromagnetic resonance (FMR) linewidth (~ 4 Oe). Shape-induced magnetic anisotropy is clearly observed in a patterned array of nanobars engineered to exhibit the larger coercivity (40 Oe) compared with that of continuous films. Both hysteresis loop and angle-dependent FMR spectra measurements indicate that the easy axis aligns along the longitudinal direction of the nanobars, with an effective anisotropy field of 195 Oe. Our work overcomes difficulties in patterning YIG thin films and provides an effective means to control their magnetic properties and magnetic bias conditions.