The Curie temperature TC is investigated as a function of the hole concentration p in thin films of ferromagnetic semiconductor (Ga,Mn)As. The magnetic properties are probed by transport measurements and p is varied by the application of an external electric field in a field-effect transistor configuration. It is found that TC ∼ pγ, where the exponent γ=0.19±0.02 over a wide range of Mn compositions and channel thicknesses. The magnitude of γ is reproduced by a p-d Zener model taking into account nonuniform hole distribution along the growth direction, determined by interface states and the applied gate electric fields.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 2010 Jan 27|