Effect of annealing on carrier density and Curie temperature in epitaxial (Ga,Mn)As thin films

TL;DR

This study investigates how annealing affects carrier density and Curie temperature in thin (Ga,Mn)As films, revealing a dependence on layer thickness and interface effects, with unique magnetoresistance features observed.

Contribution

It demonstrates the relationship between annealing, carrier density, and Curie temperature in thin (Ga,Mn)As layers, emphasizing the role of the interface.

Findings

Curie temperature correlates with carrier density changes upon annealing.

Layer thickness influences the annealing effects.

Unique magnetoresistance features are observed in thin layers.

Abstract

We report a clear correspondence between changes in the Curie temperature and carrier density upon annealing in epitaxially grown (Ga,Mn)As layers with thicknesses in the range between 5 nm and 20 nm. The changes are dependent on the layer thickness, indicating that the (Ga,Mn)As - GaAs interface has importance for the physical properties of the (Ga,Mn)As layer. The magnetoresistance shows additional features when compared to thick (Ga,Mn)As layers, that are at present of unknown origin.