Flux‐grown synthetic calciumchlorapatite (Ca10 (PO4)6Cl2) single crystals are known to show significant off‐stoichiometry; the CaCl2 deficiency can be as large as 3 to 5%. This has severe implications for many physical properties of these materials; especially the defects as produced by means of X‐rays will be strongly modified by the presence of large concentrations of vacancies. It is found that at 300 K predominantly complex colour centres are created. Below 50 K rather simple electron‐excess centres are formed during X‐irradiation. A systematic study of the photo‐chemical bleaching and annealing properties of the colour centres enables one to develop models for the electron‐excess centres observed at different temperatures.
E P R and optical absorption experiments a t 300 K on X-irradiated synthetic calciumchlorapatite single crystals doped with NaCl are presented. Two different E P R signals due t o electron-excess centres have been observed. The signals are assigned to two types of F-like colour centres, for which models are given. Es wurden bei 300 K durch Rontgenstrahlen erzeugte Farbzentren in synthetischen Einkristallen von Kalziumchlorapatit, dotiert mit NaCI, mit E P R und optischen Absorptionsmessungen untersucht. Zwei verschiedene EPR-Signale, die von ElektronenuberschuOzentren stammen, werden beobachtet. Die Signale werden zwei verschiedenen F-artigen Farbzentren zugeschrieben, fur die Modelle aufgestellt werden.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.