We discuss a model for diluted magnetic semiconductors (DMS) appropriate for low charge carrier density and local moment concentrations in III-V DMS such as Ga1-xMnxAs. In our model, carriers arise from the Mn impurity band and are exchange-coupled to the magnetic ions. We have studied this model using mean-field and Monte Carlo techniques. We find that disorder in the Mn ion locations can lead to spatially inhomogeneous local magnetizations below the Curie temperature that are strongly correlated with the local carrier charge density. This motivates a phenomenological two component model that provides an adequate description of thermodynamic properties.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics