Mollwo-Ivey relation between peak color-center absorption energy and average oxygen ion spacing in several oxides of group-II and -III metals

Color centers in neutron-irradiated Y3Al5O12, CAF2 and LiF single crystals

“…F and F + centers can be identified by their absorption band centered at about 243 or 380 nm, respectively [19,21]. However, less work has been devoted to thermal annealing studies of point defects in such materials after neutron irradiation.…”

“…Color centers induced in the Y 3 Al 5 O 12 crystal by lowly ionizing radiation (g-rays, electrons, protons and neutrons) have been studied intensively in the past [19][20][21][22][23][24][25]. F and F + centers can be identified by their absorption band centered at about 243 or 380 nm, respectively [19,21].…”

Multi-Photon Phosphor Feasibility Research

“…Defects typically manifest themselves in absorption that, depending on the defect, can be found in the spectral range from VUV to visible. One has the Mollwo-Ivey relation [37] describing correlation between peak color center absorption and average oxygen ion spacing in oxides of group II and III metals (the absorption energy increases as the distance decreases). It can be used to predict the deleteriousness of the specific defect with respect to the activator in terms of positioning of the absorption bands in various lattices.…”

Dielectric relaxations in undoped, Ce-doped and Ce,Zr-codoped Lu3Al5O12 single crystals

“…Therefore, in irradiated undoped and doped LuAG, we propose that photo-electrons and -holes are trapped at spatially correlated oxygen vacancies and oxygen ions, respectively, forming F + centers [29][30][31][32][33][34] and O À ions [33][34][35][36]. The dipoles detected in our experiments are [(F + ) 0 À(O À ) ], in Kroger-Vink notation.…”

“…It is well-known that Ce 3+ ions cause strong absorption bands at 347 and 447 nm [10,39] owing to their 4f-5d 2 and -5d 1 transitions. Evaluation of polarization of the F + center luminescence at 400 nm in YAG led to the proposal that F + centers might be perturbed by an adjacent Y Al antisite defect [29][30][31][32][33][34]. Recent survey of induced absorption features in the aluminum perovskites and garnets [33] points to the possibility of UV-visible absorption bands due to O À polaron centers [34][35][36].…”