Lower mantle phase transitions may generally have negative pressure‐temperature slopes
Open Access
- 1 September 1980
- journal article
- Published by American Geophysical Union (AGU) in Geophysical Research Letters
- Vol. 7 (9) , 709-711
- https://doi.org/10.1029/gl007i009p00709
Abstract
Phase transitions in oxides at pressures above about 150 kbar may commonly have negative pressure‐temperature slopes. The causes of the higher entropies of denser phases include low frequency vibrations of small atoms in sites having high coordination number and long metal‐oxygen distances, decrease in directional bonding, positional disorder and possible solid‐electrolyte behavior, and semiconductor‐metal and metal‐metal transitions.Keywords
This publication has 22 references indexed in Scilit:
- Solid Electrolyte Behavior of NaMgF 3 : Geophysical ImplicationsScience, 1979
- Calorimetric study of the stability of high pressure phases in the systems CoOSiO2 and “FeO”SiO2, and calculation of phase diagrams in MOSiO2 systemsPhysics of the Earth and Planetary Interiors, 1979
- Calorimetry: Its Application to PetrologyAnnual Review of Earth and Planetary Sciences, 1979
- Proof in scienceEos, 1979
- Slaty cleavage and related strain in Martinsburg Slate, Delaware Water Gap, New JerseyAmerican Journal of Science, 1978
- Calculation of effect of cation disorder on silicate spinel phase boundariesEarth and Planetary Science Letters, 1977
- Rutile-type compounds. IV. SiO2, GeO2 and a comparison with other rutile-type structuresActa Crystallographica Section B: Structural Science, Crystal Engineering and Materials, 1971
- Activity-composition relations in the systems CoOZnO and NiOZnO at 1050°CJournal of Inorganic and Nuclear Chemistry, 1971
- Effective ionic radii in oxides and fluoridesActa Crystallographica Section B: Structural Science, Crystal Engineering and Materials, 1969
- Temperature Dependence of Properties of Magnesium FerriteJournal of the American Ceramic Society, 1966