High quality GaMnAs films grown with As dimers

TL;DR

This paper reports the successful growth of high-quality GaMnAs films using As2, achieving higher Curie temperatures and broader Mn concentration ranges with improved structural and magnetic properties compared to As4-grown films.

Contribution

It introduces a novel growth method using As2 that enhances the quality and magnetic properties of GaMnAs films, expanding the range of Mn concentrations with metallic conduction.

Findings

Achieved a Curie temperature of 112K with As2-grown films.

Obtained metallic conduction over Mn concentrations from 1.5% to 8%.

Lower antisite defect concentration improves film quality.

Abstract

We demonstrate that GaMnAs films grown with As2 have excellent structural, electrical and magnetic properties, comparable or better than similar films grown with As4. Using As2, a Curie temperature of 112K has been achieved, which is slightly higher than the best reported to date. More significantly, films showing metallic conduction have been obtained over a much wider range of Mn concentrations (from 1.5% to 8%) than has been reported for films grown with As4. The improved properties of the films grown with As2 are related to the lower concentration of antisite defects at the low growth temperatures employed.