High ferromagnetic phase transition temperatures in GaMnAs layers annealed under arsenic capping

TL;DR

This study demonstrates that arsenic capping during annealing of GaMnAs layers significantly enhances ferromagnetic transition temperatures by promoting efficient Mn interstitial out-diffusion, leading to improved magnetic properties.

Contribution

It introduces a novel arsenic capping method that accelerates annealing and enhances ferromagnetic transition temperatures in GaMnAs layers.

Findings

Arsenic capping shortens annealing time needed for optimal properties.

Arsenic capping facilitates complete Mn interstitial removal.

Enhanced ferromagnetic transition temperatures achieved.

Abstract

Thin GaMnAs layers grown by molecular beam epitaxy were subjected to low-temperature post growth annealing, with an amorphous arsenic capping layer deposited on the GaMnAs surface directly after the epitaxial growth. It is shown that the presence of arsenic capping at the GaMnAs surface significantly shortens the post-growth annealing times and facilitates a complete out-diffusion of Mn interstitials from GaMnAs volume.