Study by Raman spectroscopy of order‐disorder phenomena occurring in some binary oxides with fluorite‐related structures

Order‐disorder phenomena in binary oxides with fluorite‐related structures were studied by Raman spectroscopy. Raman spectra of disordered phases show broad bands, defects leading to selection rule breakdown. For well‐ordered structures, the scattering active modes observed are those allowed by crystal symmetry. Broadening of Raman peaks occurs when order defects are present: antiphase boundaries, distribution of different cations on equivalent crystallographic positions.