Ultrahigh-pressure generation above 50 GPa in a Kawai-type large-volume press

The ability to generate high pressures in a large-volume press (LVP) is crucial for the study of matter under extreme conditions. Here, we have achieved ultrahigh pressures of ∼60 and 50 GPa, respectively, at room temperature and a high temperature of 1900 K within a millimeter-sized sample volume in a Kawai-type LVP (KLVP) using hard tungsten carbide (WC) and newly designed assemblies. The introduction of electroconductive polycrystalline boron-doped diamond and dense alumina wrapped with Cu foils into a large conventional cell assembly enables the detection of resistance variations in the Fe2O3 pressure standard upon compression. The efficiency of pressure generation in the newly developed cell assembly equipped with conventional ZK10F WC anvils is significantly higher than that of conventional assemblies with some ultrahard or tapered WC anvils. Our study has enabled the routine generation of pressures exceeding 50 GPa within a millimeter-sized sample chamber that have been inaccessible with traditional KLVPs. This advance in high-pressure technology not only breaks a record for pressure generation in traditional KLVPs, but also opens up new avenues for exploration of the properties of the Earth’s deep interior and for the synthesis of novel materials at extreme high pressures.