Electrical properties of Cd-substituted copper ferrites

Room temperature resistivity measurements were carried out for Cu1-xCdxFe2O4 ferrite samples for 0.0 less than or equal to x less than or equal to 1.0 prepared by ceramic method. At lower Cd concentration, the increase in DC resistivity is attributed to the hindering of the hopping mechanism between Fe2+ and Fe3+. This may be due to the stable bond formation of Cu3+ + Fe2+ at octahedral sites. The decrease in resistivity at higher Cd content is attributed to the lower concentration of the stable bond of Cu3+ + Fe2+. Two distinct regions have been noted for temperature dependent resistivity, namely paramagnetic and ferrimagnetic regions. Activation energy in paramagnetic region is greater than in the ferrimagnetic region which shows hopping conduction at higher temperatures. Seebeck coefficient (a) was measured for all the samples which shows that all the CuCd ferrite samples are degenerate-type semiconductors. (C) 2002 Elsevier Science B.V. All rights reserved.