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

The magnetic and structural properties of InAs:Mn self-organized diluted magnetic quantum dots grown by low-temperature (∼270°C), solid-source molecular-beam epitaxy using a very low InAs growth rate (<0.1ML∕s) are investigated. A Curie temperature (TC) of ∼350K 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 TC the effects of magnetic and structural disorder introduced by a random incorporation and inhomogeneous distribution of Mn atoms amongst the InAs quantum dots.