Manifestation of spin-spin interaction between oxygen vacancy and magnesium in ZnMgO nanorods by electron paramagnetic resonance studies

A strong spin-spin interaction between oxygen vacancy and Mg in ZnMgO nanorods has been manifested by electron paramagnetic resonance (EPR) studies from symmetrical hyperfine structure. Mg probably occupies Zn sites as a result of meta-stable coordination. 25 Mg have nuclear spin I = 5/2 that can give rise to spin resonance with the unpaired spin S = 1/2 of V-O(+) in ZnO having (2n + 1) = number of splitting as observed in the EPR spectra. On heating at 500 degrees C, the hyperfine structure disappears as Mg moves to the interstitial sites. The results are further supported by x-ray diffraction and photoluminescence results. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3659297]