Study of electron transition energies between anions and cations in spinel ferrites using differential UV–vis absorption spectra

• Published in: Physica. B, Condensed matter Condensed matter, 2016-07, Vol.492, p.61-64
• Main Authors: Xue, L.C., Wu, L.Q., Li, S.Q., Li, Z.Z., Tang, G.D., Qi, W.H., Ge, X.S., Ding, L.L.
• Format: Article
• Language: English
• Subjects: Crystal structure; Electron transition energy; Spinel ferrite; UV–vis absorption spectra
• ISSN: 0921-4526; 1873-2135
• DOI: 10.1016/j.physb.2016.04.002

It is very important to determine electron transition energies (Etr) between anions and different cations in order to understand the electrical transport and magnetic properties of a material. Many authors have analyzed UV–vis absorption spectra using the curve (αhν)2 vs E, where α is the absorption coefficient and E(=hν) is the photon energy. Such an approach can give only two band gap energies for spinel ferrites. In this paper, using differential UV–vis absorption spectra, dα/dE vs E, we have obtained electron transition energies (Etr) between the anions and cations, Fe2+ and Fe3+ at the (A) and [B] sites and Ni2+ at the [B] sites for the (A)[B]2O4 spinel ferrite samples CoxNi0.7−xFe2.3O4 (0.0≤x≤0.3), CrxNi0.7Fe2.3−xO4 (0.0≤x≤0.3) and Fe3O4. We suggest that the differential UV–vis absorption spectra should be accepted as a general analysis method for determining electron transition energies between anions and cations.