Structural and magnetic changes induced by high energy ball milling of CdFe2O4

Bulk CdFe2O4 was synthesized by solid state reaction and the corresponding fine particles were produced by using high energy ball milling. The structural and magnetic changes induced by milling were investigated. The oxides were characterized by X-ray diffraction, Mossbauer spectroscopy and vibrating sample magnetometer measurements. A general decrease in the lattice constant with increasing milling time is attributed to structural defects induced by milling. The Mossbauer spectra indicate the paramagnetic or superparamagnetic spin state in all the samples at room temperature. Magnetization increases with reduction in particle size. This can be explained by the redistribution of Cd ions in both tetrahedral and octahedral sites. The coercive field and magnetization of the milled CdFe2O4 oxide are found to be more sensitive to temperature change compared to those of the bulk compound. The coercive field for the 50 h milled oxide increases from 9 Oe at 300 K to 520 Oe at 10 K and for the bulk sample a smaller increase from 9 Oe at 300 K to 200 Oe at 10 K occurs. The temperature dependence of magnetization reveals re-entrant spin glass behavior of the compounds. (C) 2013 Elsevier B.V. All rights reserved.