Comment on "Mn Interstitial Diffusion in (Ga,Mn)As"

TL;DR

This paper discusses how As capping accelerates the annealing process in (Ga,Mn)As by affecting surface trapping of Mn interstitials, challenging the idea that diffusion is the limiting factor.

Contribution

It reveals that surface trapping, not diffusion, controls the annealing modifications in (Ga,Mn)As when using As capping.

Findings

As capping accelerates annealing effects

Surface trapping dominates over diffusion rate

Modifications are surface-trapping limited

Abstract

The magnetic and transport properties of (GaMn)As are known to be influenced by postgrowth annealing, and it is generally accepted that these modifications are due to outdiffusion of Mn interstitials. We show that the annealing-induced modifications are strongly accelerated if the treatment is carried out under As capping. This means that the modification rate is not limited by the diffusion process, but rather by the surface trapping of the diffusing species.