Cryogenic Magnetization Dynamics in Chemically Stabilized, Tensile-Strained Ultrathin Yttrium Iron Garnets with Tunable Magnetic Anisotropy

TL;DR

This study demonstrates that chemically stabilized, tensile-strained ultrathin YIG films grown by pulsed laser deposition exhibit ultralow damping and tunable magnetic anisotropy at cryogenic temperatures, suitable for spintronic applications.

Contribution

It reveals that interfacial chemical stability and growth kinetics suppress damping losses in ultrathin YIG films, enabling their use at cryogenic temperatures.

Findings

Ultralow damping constants achieved in tensile-strained YIG films.

Suppression of interdiffusion enhances low-temperature magnetic properties.

Enhanced chemical stability leads to improved film performance at nanometer scale.

Abstract

We report an interfacial chemical stability-driven reduction of low-temperature damping losses in tensile-strained, ultrathin Y3Fe5O12 (YIG) films grown by pulsed laser deposition, exhibiting ultralow damping constants and tunable magnetic anisotropy. Comparative broadband FMR measurements show that tensile-strained YIG films on Gd3Sc2Ga3O12 (GSGG) retain measurable damping even at nanometer thicknesses and cryogenic temperatures down to 2 K, outperforming relaxed films on Gd3Ga5O12. Based on static magnetometry measurements along with microstructural and compositional analyses, we attribute these enhanced dynamic properties to the suppression of interdiffusion across the YIG/GSGG interface, resulting from enhanced chemical stability and favorable growth kinetics by the presence of Sc. Our findings highlight the importance of chemical and kinetic factors in achieving few-nanometer-thick YIG film with negligible low-temperature damping dissipation and perpendicular magnetic anisotropy for cryogenic spintronic applications.