Depth profile high-energy spectroscopic study of Mn-doped GaN prepared by thermal diffusion

TL;DR

This study investigates the depth profile and magnetic properties of Mn-doped GaN prepared by thermal diffusion, revealing Mn ion distribution, valence state, and magnetic behavior differences based on substrate type.

Contribution

It provides detailed spectroscopic analysis of Mn diffusion, valence state, and magnetic properties in Mn-doped GaN prepared by a low-temperature thermal diffusion method.

Findings

Mn ions diffuse approximately 70 Å into GaN substrates.

Mn ions are in the divalent Mn$^{2+}$ state and are mainly paramagnetic.

Weak hysteresis observed in p-type GaN, paramagnetism in n-type GaN.

Abstract

We have performed an $in$-$situ$ depth profile study of Mn-doped GaN prepared by a low temperature thermal diffusion method using photoemission and x-ray absorption spectroscopy. It was revealed from the core-level photoemission measurements that Mn ions are diffused into a deep ($\sim$ 70 \AA) region of the GaN substrates and that the line shapes of Mn 3$d$ partial density of states obtained by resonant photoemission measurements was close to that of Ga$_{1-x}$Mn$_x$N thin films grown by molecular-beam epitaxy. From x-ray absorption spectroscopy (XAS) and x-ray magnetic circular dichroism (XMCD) measurements at the Mn $L$-edge, it was revealed that the doped Mn ions were in the divalent Mn$^{2+}$ state and primarily paramagnetic. In magnetization measurements, weak hysteresis was detected in samples prepared using $p$-type GaN substrates while samples using $n$-type GaN substrates showed only paramagnetism.