Matter and Radiation at Extremes, 2016, 1 (5): 269, Published Online: May. 9, 2017
Thermal equation of state of a natural kyanite up to 8.55 GPa and 1273 K
Kyanite Kyanite X-ray diffraction X-ray diffraction Thermal equation of state Thermal equation of state High-pressure and high-temperature High-pressure and high-temperature Kyanite decomposition Kyanite decomposition Thermodynamic calculation Thermodynamic calculation
Abstract
The thermal equation of state of a natural kyanite has been investigated with a DIA-type, cubic-anvil apparatus (SAM85) combined with an energy-dispersive synchrotron X-ray radiation technique up to 8.55 GPa and 1273 K. No phase transition was observed in the studied pressuretemperature (P-T ) range. The Le Bail full profile refinement technique was used to derive the unit-cell parameters. By fixing the bulk modulus K0 as 196 GPa and its pressure derivative K'0 as 4, our P-V (volume)-T data were fitted to the high temperature BircheMurnaghan equation of state. The obtained parameters for the kyanite are: V0=294.05(9)(10-10)3, α02.53(11)× 10-5K-1 and (?K/?T )P =-0.021(8) GPa?K-1. These parameters have been combined with other experimentally-measured thermodynamic data for the relevant phases to calculate the P-T locus of the reaction kyanite = stishovite+ corundum. With this thermodynamically constrained phase boundary, previous high-pressure phase equilibrium experimental studies with the multi-anvil press have been evaluated.
Qiang He, Xi Liu, Baosheng Li, Liwei Deng, Wei Liu, Liping Wang. Thermal equation of state of a natural kyanite up to 8.55 GPa and 1273 K[J]. Matter and Radiation at Extremes, 2016, 1(5): 269.