Planar array of self-assembled Ga$_{x}$Fe$_{4-x}$N nanocrystals in GaN: Magnetic anisotropy determined via ferromagnetic resonance

TL;DR

This study investigates the magnetic anisotropy of Ga$_{x}$Fe$_{4-x}$N nanocrystals embedded in GaN, revealing primarily uniaxial anisotropy with weak in-plane symmetry, using ferromagnetic resonance and microscopy techniques.

Contribution

It provides a detailed analysis of the magnetic anisotropy origins in Ga$_{x}$Fe$_{4-x}$N nanocrystals within GaN, combining experimental techniques and morphological considerations.

Findings

Magnetic anisotropy is mainly uniaxial with the hard axis normal to the NCs plane.

Weak in-plane hexagonal symmetry of the anisotropy.

The anisotropy origin involves morphology, strain, and magnetic coupling.

Abstract

The magnetic anisotropy of a planar array of Ga$_{x}$Fe$_{4-x}$N nanocrystals (NCs) embedded in a GaN host is studied by ferromagnetic resonance. X-ray diffraction and transmission electron microscopy are employed to determine the phase and distribution of the nanocrystals. The magnetic anisotropy is found to be primarily uniaxial with the hard axis normal to the NCs plane and to have a comparably weak in-plane hexagonal symmetry. The origin of the magnetic anisotropy is discussed taking into consideration the morphology of the nanocrystals, the epitaxial relations, strain effects and magnetic coupling between the NCs.