Depth profile photoemission study of thermally diffused Mn/GaAs (001) interfaces

TL;DR

This study used photoemission spectroscopy to analyze how Mn diffuses and reacts within GaAs (001) interfaces at various depths, revealing the formation of localized Mn states and ferromagnetism in the material.

Contribution

It provides detailed depth profile insights into Mn diffusion, reaction, and electronic states in Mn/GaAs interfaces, which were not previously characterized in such detail.

Findings

Mn diffuses deeply into GaAs and reacts completely.

Mn 3d states are localized and hybridized with GaAs.

Ferromagnetism observed in dilute Mn phase.

Abstract

We have performed a depth profile study of thermally diffused Mn/GaAs (001) interfaces using photoemission spectroscopy combined with Ar$^+$-ion sputtering. We found that Mn ion was thermally diffused into the deep region of the GaAs substrate and completely reacted with GaAs. In the deep region, the Mn 2$p$ core-level and Mn 3$d$ valence-band spectra of the Mn/GaAs (001) sample heated to 600 $^{\circ}$C were similar to those of Ga$_{1-x}$Mn$_x$As, zinc-blende-type MnAs dots, and/or interstitial Mn in tetrahedrally coordinated by As atoms, suggesting that the Mn 3$d$ states were essentially localized but were hybridized with the electronic states of the host GaAs. Ferromagnetism was observed in the dilute Mn phase.