Search results for "Lattice defects"
showing 3 items of 3 documents
Light Sensitive Lattice Defects In BaTiO 3 Containing Fe
1989
Electron spin resonance spectra, which can consistently be explained by the models Fe4+ - Vo and Fe5+ - vBa, have been observed with BaTiO3 containing Fe. Also Fe3+ and - Fe3+ - Vo have been identified. All these centers as well as several unidentified ones are observed to change their charge states under illumination. They thus are possibly in involved in photorefractive processes in BaTiO3 containing Fe.
Quasimolecular luminescence centers formed by photoinduced recombination of exciton-created defects in KI
1995
Abstract The photoinduced recombination of exciton-created lattice defects - the F,H center pairs was studied in KI crystal at low temperatures. Two different luminescence centers with quasimolecular structure can be distinguished. One of them is the self-trapped exciton, the other one could be the H-plus-electron (H+e) center.
Positron detrapping from defects: A thermodynamic approach
1981
The rate of positron detrapping in thermal equilibrium from lattice defects has been calculated by relating it to the specific trapping rate. The results for vacancies, dislocations and surfaces each show a different temperature dependence for the escape rate. For vacancies a measure of the importance of the detrapping can be obtained from the ratio of the vacancy formation energy to the positron binding energy in the defect. The positronium desorption rate from a surface is also calculated and agreement with experimental results is found.