A facile gel-combustion route for fine particle synthesis of spinel ferrichromite: X-ray and Mössbauer study on effect of Mg and Ni content

•A novel and facile synthesis route.•Transformation of system from random to inverse spinel.•Appearance of superparamagnetism phase.

A novel nitrate–citrate gel combustion route was used to prepare fine particle of a series Mg1−xNixFeCrO4 (0.0 ≤ x ≤ 1.0) and its structural properties were investigated. The in situ oxidizing environment provided by the nitrate ions in the gel increases the rate of oxidation and lowers the decomposition temperature of component. All the samples after sintering were characterized at room temperature by X-ray diffraction (XRD) method and Mössbauer spectroscopy techniques. The X-ray and Mössbauer studies confirmed the single phase cubic spinel structure with all Fe ions in 3+ charge state. XRD and Mössbauer studies revealed that the samples of x = 0.0, and 0.2 are random spinel and show rather broad lines, while x = 0.4–1.0 are inverse spinel.

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