$$\mathrm{AB}_{2} \text {Se}_{4}$$ Ordered-Vacancy Compounds at High Pressures

Structural and Vibrational Properties of CdAl2S4 under High Pressure: Experimental and Theoretical Approach

“…It can be observed that the peaks in the medium-and highfrequency regions shift to higher frequencies as pressure increases whereas most of the peaks of the low-frequency region show a small positive or even negative pressure coefficient, as has been observed for other AB 2 X 4 OVCs. 7,8 In general, our experimental Raman-mode frequencies and pressure coefficients at zero pressure for DC-CdAl 2 S 4 agree with those reported in previous works 11,13 and with our theoretical values. Therefore, the application of pressure allows the symmetry of the experimental Raman modes to be identified with the help of ab initio calculations.…”

“…In the past decade, interest in understanding the high-pressure (HP) behavior of OVCs at ambient temperature has increased, as recently reviewed. − Most HP studies of OVCs have focused on selenides, and only a few have considered tellurides and sulfides. − In particular, DC-CdAl 2 S 4 has been the subject of several HP X-ray diffraction (XRD) and Raman scattering (RS) studies. ,, These works provided contradictory results regarding the structure of the recovered sample after pressure loading. On the other hand, a recent study predicted that CdAl 2 S 4 is a compound that is borderline between spinel-type and defect chalcopyrite-type AB 2 X 4 compounds .…”