Effects of NiO addition on the structure and electric properties of Dy3-xNixFe5O12 garnet ferrite

Polycrystalline garnet ferrites Dy3-xNixFe5O12 with varying Ni substitutions (x = 0.0, 0.1, 0.2, 03, 0.4, and 0.5) have been prepared by the standard ceramic technique and their crystalline structures were investigated by using X-ray diffraction and IR spectroscopy. The X-ray diffraction analysis showed that all samples have a single cubic garnet phase. The materials prepared are identified by infrared rays which indicate the presence of three absorption bands nu(2), nu(3) and nu(4) which represent the tetrahedral, octahedral and dodecahedral sites respectively which characterize the garnet ferrite. The dielectric constant (epsilon), and dielectric loss (tan delta) of the prepared samples were measured at 1 kHz in the temperature range 300-700 K. The dielectric constant (epsilon), and dielectric loss (tan delta) are functions of temperature. The initial magnetic permeability has been studied at different temperatures. The initial magnetic permeability (mu(i)) increases gradually with increasing temperature and then drops suddenly at a certain temperature T-C. (C) 2009 Elsevier Masson SAS. All rights reserved.