Structural, electrical and magnetic properties of nanosize and bulk Ni_0.7Zn_0.3Fe₂O₄ obtained by thermal autocatalytic decomposition of Ni_0.7Zn_0.3Fe₂(C₄H₂O₄)₃·6N₂H₄ precursor

Nanosized Ni_0.7Zn_0.3Fe₂O₄ was synthesized by combustion of fumarato-hydrazinate precursor of metals having formula Ni_0.7Zn_0.3Fe₂(C₄H₂O₄)₃·6N₂H₄. The precursor was chemically analyzed and was subjected to TG–DTG–DTA and infrared spectroscopy (IR) studies. The decomposition of the precursor was also studied isothermally at predefined temperature along with hydrazine estimation. The X-ray diffraction (XRD), IR, transmission electron microscopy (TEM), scanning electron microscopy, thermal analysis (TG–DTA), AC susceptibility and vibrating sample magnetometry were employed to investigate structural, thermal, electric and magnetic aspects of the ‘as prepared’ and ‘sintered’ Ni_0.7Zn_0.3Fe₂O₄ along with precursor. The nanosized single phase formation of ‘as prepared’ Ni_0.7Zn_0.3Fe₂O₄ was confirmed by XRD, IR and TEM. The XRD of sintered sample showed formation of impurity free Ni_0.7Zn_0.3Fe₂O₄ while AC susceptibility studies showed lower Curie temperature than ‘as prepared’ oxide with predominantly MD type of particles. The sintered sample also showed higher saturation magnetization and lower coercivity as compared to the ‘as prepared’ sample. The ZFC–FC studies revealed decrease in blocking temperature with increasing applied magnetic field.