Defect-mediated ferromagnetism in ZnO:Mn nanorods


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Yilmaz S., McGlynn E., BACAKSIZ E., Bogan J.

APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING, cilt.115, sa.1, ss.313-321, 2014 (SCI-Expanded) identifier identifier

Özet

In this work, the structural, chemical and magnetic properties of ZnO:Mn nanorods were investigated. Firstly, well-aligned ZnO nanorods with their long axis parallel to the crystalline c-axis were successfully grown by the vapor phase transport technique on Si substrates coated with a ZnO buffer layer. Mn metal was then diffused into these nanorods at different temperatures in vacuum. From SEM results, ZnO:Mn nanorods were observed to have diameters of similar to 100 nm and lengths of 4 mu m. XPS analysis showed that the Mn dopant substituted into the ZnO matrix with a valence state of +2. Magnetic measurements performed at room temperature revealed that undoped ZnO nanorods exhibit ferromagnetic behavior which may be related to oxygen vacancy defect-mediated d (0) ferromagnetism. ZnO:Mn samples were seen to show an excess room temperature ferromagnetism that is attributed to the presence of oxygen vacancy defects forming bound magnetic polarons involving Mn.