Physics
Scientific paper
Oct 1998
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1998georl..25.3635a&link_type=abstract
Geophysical Research Letters, Volume 25, Issue 19, p. 3635-3638
Physics
3
Mineral Physics: High-Pressure Behavior, Mineral Physics: Physical Thermodynamics, Mineralogy And Petrology: Experimental Mineralogy And Petrology
Scientific paper
Quartz-type GeO2 was compressed at room temperature up to pressures of 11, 15 and 18 GPa, and the samples recovered to 1 atm were mostly amorphized. Measured densities of the amorphous phases increased with increasing synthesis pressure: the amorphous phase synthesized at 18 GPa was 32% denser than GeO2 quartz. Enthalpies of the amorphous phases relative to GeO2 quartz and glass prepared at 1 atm were measured by lead borate solution calorimetry. The enthalpies increased almost linearly with decreasing molar volumes from GeO2 quartz to the 18 GPa-amorphous phase. The enthalpy of the 18 GPa-amorphous phase was about 18 kJ/mol higher than GeO2 quartz, and about 4 kJ/mol higher than the 1 atm-glass. The higher enthalpy relative to GeO2 quartz is interpreted as the energy associated with disordering of the quartz structure and collapse of the tetrahedral framework which lead to octahedral coordination of germanium atoms.
Akaogi Masaki
Honda Takahiro
Ito Emi
Kojima R.
Nakai Issao
No associations
LandOfFree
Enthalpy and density measurements of pressure-amorphized GeO2 quartz does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Enthalpy and density measurements of pressure-amorphized GeO2 quartz, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Enthalpy and density measurements of pressure-amorphized GeO2 quartz will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1721489