Structural, electrical and magnetic properties of nanosize and bulk Ni sub(0.7)Zn sub(0.3)Fe sub(2)O sub(4) obtained by thermal autocatalytic decomposition of Ni sub(0.7)Zn sub(0.3)Fe sub(2)(C sub(4)H sub(2)O sub(4)) sub(3)·6N sub(2)H sub(4) precursor

Abstract

Nanosized Ni sub(0.7)Zn sub(0.3)Fe sub(2)O sub(4) was synthesized by combustion of fumarato-hydrazinate precursor of metals having formula Ni sub(0.7)Zn sub(0.3)Fe sub(2)(C sub(4)H sub(2)O sub(4)) sub(3)·6N sub(2)H sub(4). 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 sub(0.7)Zn sub(0.3)Fe sub(2)O sub(4) along with precursor. The nanosized single phase formation of 'as prepared' Ni sub(0.7)Zn sub(0.3)Fe sub(2)O sub(4) was confirmed by XRD, IR and TEM. The XRD of sintered sample showed formation of impurity free Ni sub(0.7)Zn sub(0.3)Fe sub(2)O sub(4) 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.