DocumentCode :
3396924
Title :
The feature of defects formation in crystallohydtates by x-ray and Uv-light
Author :
Baltabekov, A.S. ; Kim, L.M. ; Kuketaev, T.A. ; Tulegulov, A.D.
Author_Institution :
Karaganda State Univ., Karaganda, Kazakhstan
fYear :
2009
fDate :
19-23 July 2009
Firstpage :
1118
Lastpage :
1119
Abstract :
The objects of research are the crystals Li2SO4middotH2O and Na2SO4middot10H2O. In monohydrates Li2SO4middotH2O after an irradiation by X-ray in a temperature range 80-300 K thermoluminescence (TL) peaks are observe with maxima at 100 K and 130 K. The similar picture is observed for Na2SO4middot10H2O with maxima at 100 K and 140 K. The peak at 100 K is dominant in both crystallohydrates. The TL peak at 100 K disappears after complete dehydration of this crystals. The exit of luminescence from waterless samples is increased more than on three order. At an irradiation of by UV-light two TL peaks are observes with practically identical lightsum. For dehydrated samples after UV-irradiation lightsum does not collect. Thus photolysis or radiolysis of water molecules results in formation of the defects in anionic subsystem and suppression of recombination luminescence. For understanding of the observable phenomena the quantum-chemical modeling was carried out. It is established, that the hydrogen atom can be captured by defects SO3 -, SO4 - and O-. As result they are <<switched off>> from recombination processes. On the other hand at interaction of the hydrogen atom with anion SO4 2- can occurs unactivation disintegration with formation SO3 - and OH-. The given processes allow to explain observable processes in crystallohydrate of the alkaline metals sulphate at an irradiation by X-ray and UV-light. Besides the phenomenon of the loss weight at crystals Na2SO4middot10H2O after irradiation is revealed. Probably it is connected to local heating by hot electrons. The given phenomenon can be used for measurement of the large radiation dozes.
Keywords :
X-ray effects; crystal defects; hot carriers; lithium compounds; negative ions; photolysis; quantum chemistry; radiolysis; sodium compounds; thermoluminescence; ultraviolet radiation effects; Li2SO4H2O; Li2SO4middotH2O crystals; Na2SO4H2O; Na2SO4middot10H2O crystals; O- defect; OH- formation; SO3 - defect; SO3 - formation; SO4 - defect; SO4 2- anion; X-ray irradiation; alkaline metals sulphate; anionic subsystem; crystallohydtates; defects formation; dehydration; hot electrons; hydrogen atom; local heating; loss weight phenomenon; monohydrates; photolysis; quantum-chemical modeling; radiation doses; radiolysis; recombination luminescence; temperature 80 K to 300 K; thermoluminescence; ultraviolet light irradiation; ultraviolet-irradiation lightsum; water molecules; waterless samples; Atomic measurements; Crystals; Dielectric materials; Heating; Hydrogen; Loss measurement; Luminescence; Radiative recombination; Temperature distribution; Temperature measurement;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Properties and Applications of Dielectric Materials, 2009. ICPADM 2009. IEEE 9th International Conference on the
Conference_Location :
Harbin
Print_ISBN :
978-1-4244-4367-3
Electronic_ISBN :
978-1-4244-4368-0
Type :
conf
DOI :
10.1109/ICPADM.2009.5252309
Filename :
5252309
Link To Document :
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