Detailed Study of IR Absorption Spectra of Manganese–Zinc Ferrites

IR absorption spectra of the Mn1−xZnxFe2O4 ferrite‐spinel system are investigated in the frequency range ν = 800 to 40 cm−1. The spectra of the second derivative d2T/dν2 are obtained from the computer processed experimental transmission spectra (T). On their basis the two complex bands ν1 and ν2 of the IR spectra are resolved into three and four components, respectively (for zinc ferrite — into three) and for the band ν3 — into two components. From the concentration dependences of the bands νm(n) (m, n = 1, 2, 3, 4) it is concluded that the vibrations, the frequencies of which are independent of zinc ferrite concentration in certain ranges x, correspond to those of separate bonds MnO, ZnO, FeO i.e. they are characteristic with respect to frequency. The spectra of the spinels investigated are analyzed in accord with the irreducible representations of the point group F43 m(Td2). Small tetrahedral structure distortions due to higher covalency of the ZnO bonds and the availability of the Jahn‐Teller ions are considered.