Large-volume multianvil cells designed for chemical synthesis at high pressures

Abstract

Two multianvil cell assemblies with octahedral edge lengths (OEL) of 18 and 25 mm have been developed, which allow sample volumes of up to 153 and 387 mm³, respectively. Pressure calibrations were performed at room temperature and 1200 °C using quenched samples, and at variable temperature using in situ synchrotron measurements. These calibrations employed 25.4 mm tungsten carbide anvils with a truncation edge length of 12 mm for the 18 mm OEL cell (18/12 configuration) and 15 mm for the 25 mm OEL cell (25/15 configuration) and yielded sample pressures of up to 10 and 7.5 GPa, respectively, at loads approaching 800 t. The measured thermal gradients at 1200 °C vary between 5–10 °C/mm (18/12) and 15–20 °C/mm (25/15). By combining large sample/reaction volumes with minimal thermal gradients, the new multianvil cell assemblies are especially useful for chemical synthesis at high-pressure, high-temperature conditions.

Keywords:

• multianvil
• large sample volumes
• high-pressure synthesis

Acknowledgements

This research has been supported by the ACS Petroleum Research Fund and the National Science Foundation (NSF) under the grant nos. 45796-AC10 and DMR-0638826, respectively. Additionally, it was partially supported by COMPRES, the Consortium for Materials Properties Research in Earth Sciences under NSF Cooperative Agreement EAR 06-49658. Portions of this work were performed at GeoSoilEnviroCARS (Sector 13), Advanced Photon Source (APS), Argonne National Laboratory. GeoSoilEnviroCARS is supported by the National Science Foundation-Earth Sciences (EAR-0217473), Department of Energy – Geosciences (DE-FG02-94ER14466) and the State of Illinois. Use of the APS was supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. W-31-109-ENG-38.

Additional information

Notes on contributors

Emil Stoyanov

Peter A. Rock Thermochemistry Laboratory and NEAT ORU, University of California at Davis, Davis, CA 95616, USA.