Evolution of optical properties of chromium spinels CdCr2O4, HgCr2S4, and ZnCr2Se4 under high pressure
Abstract
We report pressure-dependent reflection and transmission measurements on ZnCr2Se4, HgCr2S4, and CdCr2O4 single crystals at room temperature over a broad spectral range 200-24000 cm-1. The pressure dependence of the phonon modes and the high-frequency electronic excitations indicates that all three compounds undergo a pressure-induced structural phase transition with the critical pressure 15 GPa, 12 GPa, and 10 GPa for CdCr2O4, HgCr2S4, and ZnCr2Se4, respectively. The eigenfrequencies of the electronic transitions are very close to the expected values for chromium crystal-field transitions. In the case of the chalcogenides pressure induces a red shift of the electronic excitation which indicates a strong hybridization of the Cr d-bands with the chalcogenide bands.
Turn this paper into a lesson
ArcXiv compiles a structured reading guide from this paper's metadata: plain-English importance, contributions, prerequisite concepts, which sections to read first, flashcards, and a quiz. Grounded in the abstract, never invented.