Synthesis, characterizations and magnetic properties of nanoscale CoVxFe2-xO4 (0.0 ≤ x ≤ 0.9) materials synthesized via sol-gel autocombustion route

Abstract

Nanostructured materials of CoVxFe2-xO4 (0.0 ≤ x ≤ 0.9) have been synthesized by sol-gel autocombustion method. Phase purity and nanocrystalline nature of the materials were examined by powder XRD measurements. Morphology and microstructure of the materials were ascertained by FESEM technique. The estimated crystallite sizes (d) decrease from 30 nm to 8 nm, as a result of progressive increase in V content, x, in CoVxFe2-xO4 materials. The values of the observed lattice parameters (a) decrease continuously as a function of increasing V content, x, i.e. from 8.349(5) Å to 8.284(5) Å for the values of x = 0.0 and x = 0.9, respectively. Alterations of M − O bond lengths in CoVxFe2-xO4 materials in FTIR studies indicate the incorporation of vanadium in cobalt ferrite. The values of the saturation magnetizations (Ms) and coercivities (Hc) of CoVxFe2-xO4 materials are found to be in the range of 77.58 emu/g – 37.76 emu/g and 1264 Oe – 991 Oe for various values of x from x = 0.0 to x = 0.9, respectively. The observed trends in magnetic parameters of CoVxFe2-xO4 materials have been interpreted on basis of increasing vanadium content in the materials, cation distributions, size and surface effects.