Nephelauxetic effect in luminescence of Cr3+-doped lithium niobate and garnets

The model based on Harrison theory of bonding is used to explain quantitatively the nephelauxetic effect in LiNbO3 and Y3Al5O12 crystals doped with chromium, studied by high-hydrostatic pressure spectroscopy. The model uses only one adjustable parameter and can also be used for other dopant–ligands systems in different compounds. We show that not only ligands, but also the second neighbors of the dopant, influence the nephelauxetic effect.