Infrared Spectra of Ferrites

TLDR

The study presents and analyzes the infrared spectra of seven divalent‑metal ferrites MFe₂O₄. Infrared spectra were recorded, revealing two interatomic vibrational bands; force constants for metal‑oxide stretching were calculated and band intensities measured, indicating predominantly ionic bonding. Electronic absorption appeared in the visible and near‑infrared, force constants matched elastic and thermodynamic properties and varied with metal‑ion distribution, and band intensities confirmed largely ionic bonding.

Abstract

The infrared spectra of 7 ferrites of the formula $M{\mathrm{Fe}}_{2}{\mathrm{O}}_{4}$, where $M$ designates a divalent metal, are presented and analyzed. Electronic absorption was observed in the visible and near-infrared regions. Two absorption bands arising from interatomic vibrations were measured and force constants calculated for the stretching of bonds between octahedral or tetrahedral metal ions and oxide ions. These force constants are in agreement with the elastic and thermodynamic properties of these compounds and are sensitive to distribution of metal ions between the alternate sites. The integrated vibrational band intensities were measured: they are compatible with predominantly ionic bonding for these structures.