Unary doping effect of A2+ (A=Zn, Co, Ni) on the structural, electrical and magnetic properties of substituted iron oxide nanostructures

Pure and unary doped iron oxide nanostructures (NSs) were synthesized by hexamethylenetetramine (HMTA)-assisted hydrothermal method. The presence of micro-strain was well analysed and estimated by Williamson-Hall (uniform deformation model) and size-strain analysis using X-ray diffraction peak broadening. The analysis confirmed that all prepared samples exhibited a positive slope which enumerated the presence of tensile micro-strain in all samples. The conductivity of the sample depicted an increasing trend with temperature in all samples which indicated their semiconducting behaviour. Further, It was observed that ZnFe2O4 NSs exhibited super-paramagnetic behaviour, while CoFe2O4 NSs exhibited ferromagnetic behaviour with a high coercivity of 1890 Oe and magnetic anisotropy constant approximately 1.35x10(5) emu Oe/g. High saturation magnetization, high dielectric constant, low electrical conductivity and low dielectric loss depicted the potential usage of synthesized ferrite nanostructures (FNSs) for microwave devices.