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arXiv · 0903.1691

Reproducibility of room temperature ferromagnetism in Zn0.95Mn0.05O and its understanding

R. N. Bhowmik·Asok Poddar·A. Saravanan
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Abstract

The present work reproduces the room temperature ferromagnetism by doping magnetic Mn atoms in diamagnetic ZnO. The ferromagnetic ordering is extended up to 640 K in mechanical milled Zn0.95Mn0.05O samples. The bulk and nanocrystalline samples are stabilized in hexagonal crystal structure with space group p63mc. The grain size and lattice strain of the samples, estimated from XRD spectrum using Williamson-Hall plot, showed a significant variation with milling time. Surface structure (morphology, distribution of grains and elements) is observed to be reasonably good from SEM picture and EDX spectrum at room temperature. The ferromagnetic ordering in bulk, milled and alloyed samples is primarily due to the diffusion of Mn(2+) ions into the lattice sites of ZnO. The enhancement of magnetic moment and ferromagnetic ordering temperature with reducing the grain size is discussed in terms of the existing theoretical predictions and experimental works. The role of mechanical milling induced disorder for the enhancement of room temperature ferromagnetism in Zn0.95Mn0.05O (dilute magnetic semiconductor) is also highlighted.

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R. N. Bhowmik, Asok Poddar, A. Saravanan. 2009-03-10. Reproducibility of room temperature ferromagnetism in Zn0.95Mn0.05O and its understanding. https://arxiv.org/abs/0903.1691

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