Magnetic Phase Separation in Diluted Magnetic System: Zn1−x Fe x O

Abstract

Single-phase diluted magnetic systems Zn1−x Fe x O have been prepared by chemical route. Structural and spectroscopic (UV–Vis and Mössbauer) studies indicate the incorporation of Fe3+ ions in the lattice sites. The UV–Vis results point to a systematic increase in the band gap with increasing Fe doping. The room temperature magnetization of Zn1−x Fe x O indicates a paramagnetic behavior which is in accordance with the Mössbauer results, illustrating quadrupolar doublet. At low temperature, the zero-field-cooled (ZFC) magnetization shows a cusp and this temperature increases systematically with decreasing particle size. The weak exchange bias effect manifested by a M–H loop shift is observed for x = 0.03. This shift is accompanied by the enhancement of coercivity. The dc magnetization results suggest the coexistence of ferromagnetic and antiferromagnetic exchange interactions for low doping of Fe, i.e., for x = 0.03.