6533b85efe1ef96bd12bf493
RESEARCH PRODUCT
High-pressure and high-temperature X-ray diffraction studies of scheelite BaWO4
D. Martinez-garciaY. Le GodecR. Lacomba-peralesDaniel ErrandoneaGuillaume MorardJ. Philippesubject
Analytical chemistryfergusonitechemistry.chemical_element02 engineering and technologyFergusonite01 natural scienceslaw.inventionhigh temperaturechemistry.chemical_compoundTungstatelawscheelite0103 physical sciencesPhase diagram010302 applied physicsEOSBarium021001 nanoscience & nanotechnologyCondensed Matter PhysicsSynchrotronX-ray diffractionCrystallographyhigh pressurechemistryScheelite[PHYS.COND.CM-GEN]Physics [physics]/Condensed Matter [cond-mat]/Other [cond-mat.other]X-ray crystallography0210 nano-technologyAmbient pressuredescription
International audience; We carried out high-pressure (HP) and high-temperature (HT) in situ ADXRD synchrotron measurements in barium tungstate (BaWO4 ) up to 7.5 GPa and 800 K. Coexistence of the scheelite and fergusonite structures was found beyond 7 GPa, both at room temperature and HT, suggesting a polymorphism zone in the P –T phase diagram. The experiments are complemented by thermodynamic calculations within the quasi-harmonic approximation. At ambient pressure, a volume thermal expansivity of 9.5 × 10− 6 K−1 was obtained for scheelite BaWO4 . At HP, the thermal expansivity of the fergusonite doubles that of scheelite. Theoretical equation of state curves at HP and HT are also presented.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2009-03-01 |