Cobalt Substitution in CuFe$_{2}$O$_{4}$ spinel and its influence on the crystal structure and phonons

TL;DR

This study investigates how cobalt substitution affects the crystal structure and phonon behavior in CuFe2O4 spinel powders, revealing structural distortions and phonon mode changes through various characterization techniques.

Contribution

It provides new insights into the structural and vibrational modifications caused by cobalt substitution in CuFe2O4 spinel, using comprehensive experimental analysis.

Findings

Crystallite sizes range from 27 to 37 nm.

Cobalt substitution induces tetragonal distortion.

Phonon spectra reveal local tetragonal distortion in mixed samples.

Abstract

In this work nanometric spinel Co${}_{1-x}$Cu${}_{x}$Fe${}_{2}$O${}_{4}$ powders were obtained by polymeric precursors method at several annealing temperatures between 700 and 1200 ${}^\circ$C. The samples were characterized by means of X-ray powder diffraction, confirming the ideal inverse spinel structure for CoFe${}_{2}$O${}_{4}$ sample and the tetragonal distorted inverse spinel structure for CuFe${}_{2}$O${}_{4}$ sample. Based on FWHM evaluation, we estimated that crystallite sizes varies between 27 and 37 nm for the non-substituted samples. The optical-active modes were determined by infrared and Raman spectroscopies. The phonon spectra showed a local tetragonal distortion for mixed samples.