LAUSR

Abstract We investigate the nature of transport and ferromagnetic properties of the epitaxial GaAs structure with the Mn δ-doped layer. To modify the properties of the structure electrically active radiation defects are created by irradiation with 50 keV helium ions and a fluence in the range of 1 × 1011–1 × 1013 cm−2. The investigations show that transport properties of the structure are determined by two parallel conduction channels (the channel associated with hole transport in a valence band and the channel associated with electron transport in the Mn-related impurity band) and that ferromagnetic properties are determined by electrons localized at allowed states within the Mn impurity band. The ferromagnetic properties of the Mn δ-layer region cannot be affected by the closely located InGaAs quantum well, since the presence of quantum well has negligible influence on the Mn impurity band filling by electrons.