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.

摘要

大容量立方体压力机广泛用于科学研究和工业应用。然而，它们的承压能力通常仅限于 6 GPa，这严重限制了它们在扩展压力下的应用。在这项工作中，我们通过将六个 WC 压力增强块嵌入叶蜡石压力传输介质中，报告了一种新设计的用于立方压机的混合电池组件，从而显着提高了压力效率（即40% 以上），因此在不牺牲样品体积的情况下，将压力条件大大扩展到 8-9 GPa。由于优化的设计，昂贵的第一级WC砧得到了有效保护，这使得压力机日常运行高达8-9 GPa，避免损坏砧。通过优化加热效率，新组件的温度可以达到2500°C以上。使用这种高压电池，我们通过六方 BN 在 7.7 GPa 和 2000°C 的直接转化合成了厘米大小的多晶立方 BN 块状样品。成功实施高达 8-9 GPa 和 2500°C 的大体积立方压机将为大规模合成新材料（例如新型超硬化合物）和研究扩展压力下的材料提供许多机会。