The thermal quenching or plastic strain of RbCI, KC1, and KBr crystals leads to an increase in the number of associations of anion and cation vacancies. Using the methods of VUV spectroscopy, electronic excitations localized near divacancies are detected at 5 K. The process of radiative and nonradiative decay of these excitations is studied as well as the process of radiational creation of divacancies.
Using synchrotron radiation of €-32 eV the reflection spectrum md excitation spectra for 5.7.4.6 and 2.8 eV emissions have been measured for a freshly cleaved CaO crystal at wCr.In CaO. indirect band-to-band m i t i o n s take place in the region of hv > 6.4 eV. The excitation spectra for intrinsic emissions of 5.9 and 4.2 eV were measured in a YAlO, crystal at LHCT a well. As in many other dielectiics the electron-hole mechanism of multiplication of electronic excitations connected with the creation of secondary electron-hole pain by hot photoelectrons also occurs in CaO and YA103 crysols. The creation ofsecondary excitons by hot photoelectrons has been detected in YAI03 for the Brst time. The excitonic mechanism of multiplication of electronic excitations has a high efficiency in crystals with self-trapping excitons of small radii.
The efficiency of α, I pair creation at exciton decay is high at 4.2 K for KCl, KBr, and RbBr crystals for which H centers are oriented along 〈110〉. The efficiency of α, I pair creation by VUV‐irradiation at 4.2 K is extremely low for NaCl crystals for which H centers are oriented along 〈111〉. The process of mobile crowdion‐type interstitial halogen ion (I center) formation in KCl, KBr, RbCl, and RbBr (but not in NaCl) due to the tunneling recharge of primary F, H pairs is discussed. Such an I crowdion can shift by several interanion distances along [110] even at 4.2 K and, as a result, the system leaves the zone of spontaneous annihilation of α and I centers.
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.