Raman spectroscopy of AMn2O4 (A = Mn, Mg and Zn) spinels

Abstract

First order Raman spectra in the region 200–800 cm⁻¹ have been collected for AMn₂O₄ (A = Mn, Mg and Zn) tetragonal spinels. A possible correlation between Raman phonons and AO₄ and MnO₆ unit vibrations is proposed. Structural changes have been analyzed following the evolution of the Raman spectra with x for the Mg_1−xMn_xMn₂O₄ solid solution; the effect of the spinel inversion has been also studied on MgMn₂O₄ quenched samples from high temperatures. The results, taking into account also the X-ray diffraction and electron paramagnetic resonance data, show the influence of the Jahn–Teller effect on the Raman scattering for this class of materials.