Operation of large-volume cubic press above 8 GPa and 2500°C with a centimeter-sized cell volume using an optimized hybrid assembly

ABSTRACT

Large-volume cubic presses are widely used in scientific research and industrial applications. However, their pressure capability is often limited to 6 GPa, which severely restricts their applications under extended pressures. In this work, we report a newly designed hybrid cell assembly for cubic presses by embedding six WC pressure-enhancing blocks into the pyrophyllite pressure-transmitting medium, leading to profoundly increased pressure efficiency (i.e. more than 40%), hence largely extended pressure conditions up to 8–9 GPa without sacrificing sample volume. Because of the optimized design, the expensive first-stage WC anvils are effectively protected, which makes the press routinely operated up to 8–9 GPa in avoiding damage of anvils. Through optimization of heating efficiency, temperature of the new assembly can reach above 2500°C. Using this high pressure cell, we have synthesized centimetre-sized polycrystalline cubic BN bulk sample by the direct transformation of hexagonal BN at 7.7 GPa and 2000°C. Successful implementation of large-volume cubic press up to 8–9 GPa and 2500°C would provide many opportunities for the synthesis of new materials on massive scale (e.g. novel superhard compounds) and for the study of materials at extended pressures.

KEYWORDS:

• Cubic press
• high pressure
• hybrid cell assembly
• superhard materials

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the Key Research Platforms and Research Projects of Universities in Guangdong Province (grant number 2018KZDXM062), the Shenzhen Science and Technology Innovation Committee (grant number JCYJ20190809173213150), the Guangdong Innovative & Entrepreneurial Research Team Program and Entrepreneurial Research Team Program (grant number 2016ZT06C279), the Shenzhen Peacock Plan (grant number KQTD2016053019134356), and the Research Platform for Crystal Growth and Thin-Film Preparation at SUSTech. The work was also partially supported by the Shenzhen Development and Reform Commission Foundation for Shenzhen Engineering Research Center for Frontier Materials Synthesis at High Pressure.