We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Positron states and nanoobjects in proton-irradiated quartz single crystals: Positronium atom in quartz.
- Authors
Grafutin, V. I.; Zaluzhnyi, A. G.; Timoshenkov, S. P.; Britkov, O. M.; Ilyukhina, O. V.; Myasishcheva, G. G.; Prokop'ev, E. P.; Funtikov, Yu. V.
- Abstract
The influence of proton bombardment and metal atom impurities on the structure of quartz single crystals has been studied. The related defects have been studied using positron annihilation spectroscopy (angular correlation of positron-annihilation photons), acoustic absorption, and optical absorption measurements. It is shown that the presence of a narrow component f in the angular distribution of annihilation photons (ADAP), which is related to the formation of parapositronium, determines a high sensitivity of this method with respect to features of the crystal structure of quartz. It is established that the defectness of the structure of irradiated quartz crystals can be characterized by the ratio f/f 0 of the relative intensities of narrow components in the ADAP curves measured before ( f 0) and after ( f) irradiation. Any process leading to a decrease in the probability of positronium formation (e.g., positron loss as a result of the trapping on defects and the interaction with impurity atoms and lattice distortions) decreases the intensity of the narrow component. Based on the ADAP data, estimates of the radii and concentrations of nanodefects in quartz have been obtained and their variation upon annealing at temperatures up to T = 873 K has been studied.
- Subjects
POSITRON emission; CRYSTALS; SPECTRUM analysis; CRYSTALLOGRAPHY; PHYSICAL &; theoretical chemistry
- Publication
Journal of Experimental & Theoretical Physics, 2008, Vol 106, Issue 4, p625
- ISSN
1063-7761
- Publication type
Article
- DOI
10.1134/S1063776108040018