Research output: Contribution to journal › Article › peer-review
Electrical conductivity and the nature of charge carriers in glasses of the Tl2O-B2O3 system. / Sokolov, I. A.; Murin, I. V.; Khripun, V. D.; Valova, N. A.; Startsev, Yu K.; Pronkin, A. A.
In: Glass Physics and Chemistry, Vol. 34, No. 3, 06.2008, p. 227-239.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Electrical conductivity and the nature of charge carriers in glasses of the Tl2O-B2O3 system
AU - Sokolov, I. A.
AU - Murin, I. V.
AU - Khripun, V. D.
AU - Valova, N. A.
AU - Startsev, Yu K.
AU - Pronkin, A. A.
PY - 2008/6
Y1 - 2008/6
N2 - The concentration dependence of the electrical conductivity of glasses in the Tl2O-B2O3 system is studied. The nature of charge carriers in this system is experimentally investigated for the first time. It is demonstrated using the Hittorf, Tubandt, and Hebb-Liang-Wagner techniques and the Faraday law that neither Tl+ ions nor electrons are involved in the electricity transport. The verification of the Faraday law does not reveal the presence of thallium in the amalgam of the cathode or a change in the sample weight after electrolysis, to within the experimental error. This allows one to make the inference that protons can be charge carriers in glasses of the Tl2O-B2O3 system. It is shown using extended X-ray absorption fine structure (EXAFS) spectroscopy that Tl3+ ions and thallium Tl0 reduced to the metallic state are absent in the structure of the glasses under investigation. This means that thallium in glasses of the Tl2O-B2O3 system occurs only in the form of Tl+ ions. The analysis of the IR spectroscopic data leads to only a qualitative conclusion that the water content in the glasses insignificantly increases with an increase in the thallium oxide content. An increase in the electrical conductivity of glasses in the Tl 2O-B2O3 system with an increase in the thallium oxide content is explained by the increase in the number of protons formed upon dissociation of H+[BO4/2]- structural-chemical units, because their concentration increases with increasing Tl2O content. In the structure of boron oxide, impurity hydrogen enters predominantly into the composition of H+[O2/2BO-] structural-chemical units, for which the dissociation energy is higher than that for the H+[BO4/2]- structural-chemical units. The increase in the concentration of H+[BO4/2]- structural-chemical units is accompanied by the increase in the number of dissociated protons, which are charge carriers in glasses of the Tl 2O-B2O3 system.
AB - The concentration dependence of the electrical conductivity of glasses in the Tl2O-B2O3 system is studied. The nature of charge carriers in this system is experimentally investigated for the first time. It is demonstrated using the Hittorf, Tubandt, and Hebb-Liang-Wagner techniques and the Faraday law that neither Tl+ ions nor electrons are involved in the electricity transport. The verification of the Faraday law does not reveal the presence of thallium in the amalgam of the cathode or a change in the sample weight after electrolysis, to within the experimental error. This allows one to make the inference that protons can be charge carriers in glasses of the Tl2O-B2O3 system. It is shown using extended X-ray absorption fine structure (EXAFS) spectroscopy that Tl3+ ions and thallium Tl0 reduced to the metallic state are absent in the structure of the glasses under investigation. This means that thallium in glasses of the Tl2O-B2O3 system occurs only in the form of Tl+ ions. The analysis of the IR spectroscopic data leads to only a qualitative conclusion that the water content in the glasses insignificantly increases with an increase in the thallium oxide content. An increase in the electrical conductivity of glasses in the Tl 2O-B2O3 system with an increase in the thallium oxide content is explained by the increase in the number of protons formed upon dissociation of H+[BO4/2]- structural-chemical units, because their concentration increases with increasing Tl2O content. In the structure of boron oxide, impurity hydrogen enters predominantly into the composition of H+[O2/2BO-] structural-chemical units, for which the dissociation energy is higher than that for the H+[BO4/2]- structural-chemical units. The increase in the concentration of H+[BO4/2]- structural-chemical units is accompanied by the increase in the number of dissociated protons, which are charge carriers in glasses of the Tl 2O-B2O3 system.
UR - http://www.scopus.com/inward/record.url?scp=45749088533&partnerID=8YFLogxK
U2 - 10.1134/S1087659608030012
DO - 10.1134/S1087659608030012
M3 - Article
AN - SCOPUS:45749088533
VL - 34
SP - 227
EP - 239
JO - Glass Physics and Chemistry
JF - Glass Physics and Chemistry
SN - 1087-6596
IS - 3
ER -
ID: 87998486