Synthesis and morphological study of chromium substituted Zn–Mn ferrites nanostructures via sol–gel method

Nanocrystalline ZnMn1−xCrxFeO4 (1.0 ≥ x ≥ 0) ferrites were prepared by sol–gel route. X-ray diffraction (XRD) method was used to confirm the formation of single phase cubic spinel lattice for all the composition. The lattice parameter (a) shows a decreasing trend with the increase in Cr content. In all the studied compositions, spherical crystalline nanoparticles of about 30 nm size were observed by transmission electron microscopy (TEM) technique. The elemental analysis as obtained from EDAX is in close agreement with the expected composition from the stoichiometry of reactant solutions used. Infrared spectroscopic studies revealed two main absorption bands in the range of 400–800 cm−1 arising due to tetrahedral (A) and octahedral (B) stretching vibrations. On substitution of Cr3+ in Mn3+ site, the stretching frequency of the octahedral site increases smoothly but that of the tetrahedral site is seen to be unaltered. The detailed results of XRD, SAED and infrared spectroscopy have been discussed so as to bring out the role of chromium substitution in determining structural properties of Zn–Mn ferrites.

Research highlights▶ Spherical crystalline nanoparticles of ZnMn1−xCrxFeO4 has been prepared by sol-gel combustion method. ▶ Site preference of Cr3+ has been concluded from IR spectroscopy techniques.