Epitaxial patterning of nanometer-thick Y3Fe5O12 films with low magnetic damping

TL;DR

This paper reports on the reliable epitaxial growth and nanopatterning of ultra-low damping Y3Fe5O12 thin films, demonstrating their potential for low-power spintronic devices through detailed magnetic and dynamic property analysis.

Contribution

It introduces a compatible fabrication process for high-quality Y3Fe5O12 nanostructures with systematic magnetic property investigation and mode analysis, including edge mode identification and size effects.

Findings

Low magnetic damping in films and structures

Identification of edge modes in nanowires

Size-dependent evolution of magnetic modes

Abstract

Magnetic insulators such as yttrium iron garnet, Y3Fe5O12, with extremely low magnetic damping have opened the door for low power spin-orbitronics due to their low energy dissipation and efficient spin current generation and transmission. We demonstrate reliable and efficient epitaxial growth and nanopatterning of Y3Fe5O12 thin-film based nanostructures on insulating Gd3Ga5O12 substrates. In particular, our fabrication process is compatible with conventional sputtering and liftoff, and does not require aggressive ion milling which may be detrimental to the oxide thin films. Structural and magnetic properties indicate good qualities, in particular low magnetic damping of both films and patterned structures. The dynamic magnetic properties of the nanostructures are systematically investigated as a function of the lateral dimension. By comparing to ferromagnetic nanowire structures, a distinct edge mode in addition to the main mode is identified by both experiments and simulations, which also exhbits cross-over with the main mode upon varying the width of the wires. The non-linear evolution of dynamic modes over nanostructural dimensions highlights the important role of size confinement to their material properties in magnetic devices where Y3Fe5O12 nanostructures serve as the key functional component.