Resumen de Effect of Cr^(3+) substitution on magnetic and electrical properties of (Ni_(0.3)Cu_(0.7)) Fe_(2)O_(4) spinel ferrites
K. Bashir, M. ul-Islam, M. Ajmal, M. Hussain, M. Waqas Nafees, A. Iftikhar, I. H. Gul, S. Naseem, Khalid Mahmood
Chromium substituted copper base spinel ferrites (Ni_(0.3)Cu_(0.7))Cr_(X)Fe_(2−X)O_(4) were prepared by Sol-gel method. Structural, magnetic and electrical properties were studied by utilizing an X-ray diffractometer, vibrating-sample magnetometer, and precision LCR-meter using labtracer software. The X-ray diffraction analysis confirmed the formation of single phase fcc structure of the samples. The lattice constant and crystallite size decreased from 8.37-8.23 Å and 53.09-35.36 nm, respectively with increasing content of Cr^(3+) ions. From Magnetization Vs Applied field loops it was observed that the saturation magnetization decreased and coercivity increased with increasing content of Cr^(3+) ions. Dc resistivity increased with increase of Cr^(3+) concentration and decreased with increase in temperature which shows the semiconducting behavior of ferrites. The dielectric constant, dielectric loss, and tangent loss decreased with increase of Cr^(3+) concentration. The dielectric constant follows bilayer Maxwell Wagner model and Koop’s phenomenological theory while ac conductivity increased with increasing frequency following Jonscher’s power law.
