Temperature Dependence of Magnetic Properties of an 18-nm-thick YIG Film Grown by Liquid Phase Epitaxy: Effect of a Pt Overlayer

TL;DR

This study investigates how temperature and a platinum overlayer influence the magnetic properties of an 18-nm YIG film grown by liquid phase epitaxy, revealing effects on anisotropy, damping, and interfacial coupling.

Contribution

It provides new insights into the temperature-dependent magnetic behavior of thin YIG films and the impact of Pt capping on their magnetic anisotropy and relaxation mechanisms.

Findings

Magnetic properties of YIG are similar to bulk behavior across 100-400 K.

Pt overlayer modifies uniaxial perpendicular anisotropy, especially at low temperatures.

Interfacial coupling increases linewidth and magnetic relaxation at lower temperatures.

Abstract

Liquid phase epitaxy of an 18 nm thick Yttrium Iron garnet (YIG) film is achieved. Its magnetic properties are investigated in the 100 -- 400 K temperature range, as well as the influence of a 3 nm thick Pt overlayer on them. The saturation magnetization and the magnetocrystalline cubic anisotropy of the bare YIG film behave similarly to bulk YIG. A damping parameter of only a few $10^{-4}$ is measured, together with a low inhomogeneous contribution to the ferromagnetic resonance linewidth. The magnetic relaxation increases upon decreasing temperature, which can be partly ascribed to impurity relaxation mechanisms. While it does not change its cubic anisotropy, the Pt capping strongly affects the uniaxial perpendicular anisotropy of the YIG film, in particular at low temperatures. The interfacial coupling in the YIG/Pt heterostructure is also revealed by an increase of the linewidth, which substantially grows by lowering the temperature.