GaMnAs: layers, wires and dots

TL;DR

This paper investigates the growth, treatment, and nanostructure formation of GaMnAs ferromagnetic semiconductors, demonstrating improved magnetic properties and the potential for creating low-dimensional structures like nanowires and dots.

Contribution

It introduces post-growth annealing with arsenic passivation to enhance magnetic properties and enables the formation of MnAs dots and nanowires on GaMnAs surfaces.

Findings

Post-growth annealing increases the ferromagnetic transition temperature.

Surface-rich MnAs layers can be used to form nanostructures.

MnAs dots facilitate the growth of Mn-doped GaAs nanowires.

Abstract

Thin layers of GaMnAs ferromagnetic semiconductor grown by molecular beam epitaxy on GaAs(001) substrates were studied. To improve their magnetic properties the post-growth annealing procedures were applied, using the surface passivation layers of amorphous arsenic. This post growth treatment effectively increases the ferromagnetic-to-paramagnetic phase transition temperature in GaMnAs, and provides surface-rich MnAs layer which can be used for formation of low dimensional structures such as superlattices. If the surface rich MnAs layer consists of MnAs dots, then it is possible to grow Mn-doped GaAs nanowires