ABSTRACT
In this paper, a pressurization-insulation and pre-sealing (PIPS) system is designed to increase the cell pressure of the widely used large volume cubic press without sacrificing cell volume. The sample chamber was sandwiched between a pair of tungsten carbide anvils used as the pressurization system. Ultra-high pressure in the cavity was up to about 12 GPa, and the pressure limit had increased by 100% in contrast with that of an anvil-gasket (AG) system. Furthermore, the confining pressure around the sample chamber was supported by grade 304 stainless steel and a zirconia-calcium oxide solid solution before a press load of 2.8 MN was applied as well as by four surrounding anvils. The relationship between the sample chamber pressure and the press load for this system was calibrated at room temperature using transitions in zinc telluride. With samples of similar volumes, the proposed system retained not only stability but also uniform pressure and temperature fields, in contrast with the AG system and the anvil-preformed gasket cubic press pressurization system. The results of more than 20 experiments show that the proposed PIPS system can operate stably under a press load of 4.2 MN, corresponding cell pressure of 10 GPa, and temperature in the cell exceeding 1800 °C by using graphite as a heater.
ABSTRACT
An anvil-preformed gasket system has been developed to extend the pressure range for the widely used large volume cubic press without sacrificing the sample volume. The relationship of the sample chamber pressure versus press load for this system was calibrated at room temperature using transitions in Bi, Tl, and Ba. With similar sample volumes (8-11 mm in diameter and 8 mm in length), the anvil-preformed gasket system can generate pressures up to about 8.5 GPa, significantly higher than 6 GPa, which was generally the maximum pressure for the conventional anvil-gasket system. The details on the optimized design for the anvil-preformed gasket system are given in this note.
