Local structure around Mn in Mn containing ZnO nanocrystals

Abstract

Among the diluted magnetic semiconductors of current interest, especially ZnO is experiencing a renaissance with the incorporation of Mn because of the recent predictions from theory. We have obtained local structure information from X-ray Absorption Spectroscopy (XAS) complementing previous electron paramagnetic resonance (EPR) studies on Mn in ZnO nanocrystals and Zn(OH)(2). Mn is found to be incorporated substitutionally into the ZnO nanocrystals with a sizeable distortion as compared to the regular ZnO lattice structure. Depending on the preparation of the nanocrystals Mn is found in the ZnO core as well as in a Zn(OH), surface shell with a fraction which decreases upon annealing as the shell disintegrates forming additional ZnO. No indications for Mn clusters were found. (c) 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim.