TY - JOUR
T1 - Enthalpies of transformation among the tetragonal, hexagonal, and glassy modifications of GeO2
AU - Navrotsky, A.
N1 - Funding Information:
Acknowledgements - The author wishes to thank M. C. Batchelder and J. Neil for technical assistance and O. J. Kleppa for valuable discussion and for the use of calorimetric facilities. This research has been aided by support from the Research Corporation and by a grant to O. J. Kleppa from the Petroleum Research Fund administered by the American Chemical Society. The author also wishes to acknowledge support from the University Grants Committee, Arizona State University, for a summer fellowship and for partial support of this research.
PY - 1971/4
Y1 - 1971/4
N2 - By means of solution calorimetry in a molten oxide solvent of composition 2PbO·B2O3 at 692±2°C, the enthalpy of transformation of tetragonal to hexagonal germania was found to be +5·17±0.25 kcal/mole, and that of hexagonal germania to glass, +3·7±0·6 kcal/mole. The heat content increment between room temperature room temperature and the calorimetric temperature. H966-H295. of the tetragonal form was measured by "transposed-temperature" drop calorimetry in order to refer these data to room temperature. The enthalpies and calculated entropies for the transformations are discussed, and compared with the corresponding values for silica.
AB - By means of solution calorimetry in a molten oxide solvent of composition 2PbO·B2O3 at 692±2°C, the enthalpy of transformation of tetragonal to hexagonal germania was found to be +5·17±0.25 kcal/mole, and that of hexagonal germania to glass, +3·7±0·6 kcal/mole. The heat content increment between room temperature room temperature and the calorimetric temperature. H966-H295. of the tetragonal form was measured by "transposed-temperature" drop calorimetry in order to refer these data to room temperature. The enthalpies and calculated entropies for the transformations are discussed, and compared with the corresponding values for silica.
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U2 - 10.1016/0022-1902(71)80180-X
DO - 10.1016/0022-1902(71)80180-X
M3 - Article
AN - SCOPUS:0038299608
SN - 0022-1902
VL - 33
SP - 1119
EP - 1124
JO - Journal of Inorganic and Nuclear Chemistry
JF - Journal of Inorganic and Nuclear Chemistry
IS - 4
ER -