Lattice parameter and hole density of (Ga,Mn)As on GaAs(311)A

摘要

We discuss the structural and electrical properties of (Ga,Mn)As layers with Mn concentrations up to 5%, grown on GaAs(311)A substrates by low-temperature molecular-beam epitaxy. High-resolution x-ray diffraction studies reveal a higher concentration of As antisites and a weaker linear increase of the relaxed lattice constant with Mn content in the (311)A layers compared to (100) reference layers. The hole densities and Curie temperatures, determined from magnetotransport measurements, are drastically reduced in the (311)A layers. The findings are explained by an enhanced incorporation of Mn atoms on nonsubstitutional and noninterstitial sites, probably as Mn-Mn or As-Mn complexes, caused by the larger amount of excess As in the (311)A layers.