Mossbauer, magnetic and electric studies on mixed Rb-Zn ferrites prepared by solution combustion method

Single phase nanosized spinel ferrites with general formula Rb0.5-x/2ZnxMn0.05Fe2.45-x/2O4 (x=0 -> 0.5) were prepared by solution combustion route using ethylene glycol as a capping agent. The ferrites obtained have been characterized by powder XRD and Mossbauer spectroscopy. Their magnetic and electric properties have been studied by employing Vibrating Sample Magnetometer (VSM), Curie temperature assembly and LCR meter. Mossbauer spectra display transition from ferrimagnetic to superparamagnetic phase. The saturation magnetization (M-S) initially exhibits an upward trend followed by regular decrease with increasing diamagnetic Zn content. Curie temperature also shows a downward trend with increasing Zn content. The resistivity of the doped samples decreases with temperature suggesting semiconductor behaviour of the ferrites. The dielectric constant (epsilon) and tangent loss (tan delta) measured at room temperature as a function of frequency show the expected ferrite behaviour. (C) 2011 Elsevier B.V. All rights reserved.