Studies on initial permeability and loss factor in Ni-Zn ferrites synthesized by oxalate precursors

NixZn1-xFe2O4 ferrites with (X = 0.28-0.40 in step of 0.2) have been synthesized by oxalate precursor method and investigated for their, initial permeability and loss factor measurements. Initial permeability has been observed to increase with the increase in Ni2+ up to X = 0.32, beyond which it decreases. The variation of initial permeability has been explained by considering the factors such as grain size, saturation magnetization and anisotropy constant. Thermal variation of initial permeability reveals a peak height in mu(i)-T curves which tends to increase with increase in Ni2+ content. mu(i)-T curves also exhibit thermal hysteresis, which reveals the inverse relationship between the difference in heating and cooling curves at which hysteresis falls between Hopkinson peak and T-c with value of initial permeability. Loss factor values are small which is attributed to high density of the samples and processing techniques. (C) 2010 Elsevier Ltd. All rights reserved.