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

Holub, M.; Chakrabarti, S.; Fathpour, S.; Bhattacharya, P.; Lei, Y.; Ghosh, S.
August 2004
Applied Physics Letters;8/9/2004, Vol. 85 Issue 6, p973
Academic Journal
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 (<0.1 ML/s) are investigated. A Curie temperature (TC) of ∼350 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 TC the effects of magnetic and structural disorder introduced by a random incorporation and inhomogeneous distribution of Mn atoms amongst the InAs quantum dots.


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