Raman study of ACu3Fe4O12 (A = Ca, Sr, Y and Eu)

• Raman study of ACu3Fe4O12 compounds containing high oxidation number of iron (Fe4+).
• Polarized Raman spectra fruitfully obtained on microcrystals with sizes of 7 μm.
• Assignment of the observed Raman modes to the correct symmetry.
• Lattice dynamics calculations were employed to study the phonon spectra.

A vibrational study of ACu3Fe4O12 (A = Ca, Sr, Y and Eu) compounds was carried out by means of micro-Raman scattering and lattice dynamics calculations. Polarized Raman scattering measurements were performed on rectangular microcrystals, with sizes close to 7 μm, and six Raman active modes were observed among the eight expected. It was then possible to assign the observed modes to the correct symmetry. Moreover, lattice dynamics calculations led to determine the main atomic displacements and a good agreement was found between experimental and theoretical wavenumbers. Furthermore, wavenumbers evolution versus A cation showed two behaviors separating the samples into two groups.

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