Structural, magnetic and electrical properties of nano NiCr_xFe_2-xO₄ synthesized by flash auto combustion method

The spinel Nano-ferrite system NiCr_xFe_2-xO₄ (where x=0.0, 0.2, 0.4, 0.6, 0.8 and 1.0) have been prepared using flash auto combustion method. The XRD pattern confirms the formation of spinel Ni-Cr ferrite for the as-prepared samples. Electrical properties of as- prepared samples such dielectric constant and AC resistivity were studied in the temperature range (288- 773 K). It was observed that the AC resistivity increases by increasing Cr content and decreases by increasing frequency. The DC electrical resistivity was found to increase by increasing Cr content from 25*10⁶ to 136*10⁶ Ω.cm, whereas it was found to decrease with increasing temperature. VSM was used to study the magnetic properties of Ni-Cr ferrite at room temperature. It was found that, with increasing Cr content the (Ms) saturation magnetization decreased from 28 to 3 emu/g whereas coercivity increased from 188 to 666 (G).The magnetic moment of the system and Curie temperature decreased by increasing Cr substitution. (paper)