Magnetooptical properties of (Ga,Fe)N layers

TL;DR

This study investigates the magnetooptical properties of (Ga,Fe)N layers containing Fe-rich nanocrystals, revealing complex magnetic behaviors and differences between magnetic measurement techniques.

Contribution

It provides new insights into the magnetooptical responses of (Ga,Fe)N layers with Fe-rich nanocrystals and discusses discrepancies between different magnetic measurement methods.

Findings

Fe-rich nanocrystals broaden excitonic features

Ferromagnetic contribution detected by SQUID magnetometry is not seen in MCD

Magnetic responses differ between MCD and SQUID measurements

Abstract

Magnetooptical properties of (Ga,Mn)N layers containing various concentrations of Fe-rich nanocrystals embedded in paramagnetic (Ga,Fe)N layers are reported. Previous studies of such samples demonstrated that magnetization consists of a paramagnetic contribution due to substitutional diluted Fe ions as well as of ferromagnetic and antiferromagnetic components originating from Fe-rich nanocrystals, whose relative abundance can be controlled by the grow conditions. The nanocrystals are found to broaden and to reduce the magnitude of the excitonic features. However, the ferromagnetic contribution, clearly seen in SQUID magnetometry, is not revealed by magnetic circular dichroism (MCD). Possible reasons for differences in magnetic response determined by MCD and SQUID measurements are discussed.