Mn-doped InAs self-organized diluted magnetic quantum-dot layers with Curie temperatures above 300 K

The magnetic and structural properties of InAs:Mn self-organized diluted magnetic quantum dots grown by low-temperature (similar to270 degreesC), solid-source molecular-beam epitaxy using a very low InAs growth rate (<0.1 ML/s) are investigated. A Curie temperature (T-C) of similar to350 K is measured in a sample grown with a Mn/In flux ratio of 0.15. Electron energy-loss spectroscopy confirms that most of the Mn remains within the InAs quantum dots. We propose as a possible explanation for this high T-C the effects of magnetic and structural disorder introduced by a random incorporation and inhomogeneous distribution of Mn atoms amongst the InAs quantum dots. (C) 2004 American Institute of Physics.