Pressure calibrations of
large-volume presses at HPSTAR - Dr. Yanhao
Lin

A research team led by Dr. Yanhao Lin at the Center for High Pressure Science and Technology Advanced Research (HPSTAR), in collaboration with other researchers at the center, has recently completed a comprehensive pressure calibration of multiple large-volume presses (LVPs) currently in operation at HPSTAR. The work updates existing pressure reference systems and establishes a standardized calibration methodology that can be applied across laboratories worldwide. The study has been published in Matter and Radiation at Extremes. The first author of this work is Dr. Yongjiang Xu, a postdoc at HPSTAR, who carried out the work in collaboration with colleagues through several years of systematic experimentation, validation, and data integration, culminating in this foundational pressure calibration work.

Large-volume presses are essential experimental devices in high-pressure physics, chemistry, materials science, and Earth and planetary sciences. They enable new material synthesis, phase transition studies, and investigations into physical properties under extreme pressure-temperature conditions. HPSTAR has installed and commissioned several state-of-the-art LVP devices in recent years, establishing a strong foundation for multidisciplinary research. However, despite the rapid expansion of facilities, these systems previously lacked unified pressure calibrations. Globally, inconsistencies in calibrant selection and data-processing strategies have also resulted in discrepancies across laboratories, affecting reproducibility and hindering direct comparison of research outcomes.

The study systematically reviews pressure calibrants used in the high-pressure community since the 1940s, covering metals and semiconductors (including bismuth, barium, lead, tellurium, Cd₃P₂, ZnSe, GaAs, and GaP) as well as mineral systems (such as quartz, fayalite, forsterite, and bridgmanite). Several pressure reference values have been updated. This work also highlights limitations associated with traditionally used calibrants such as ZnS and ZnTe and proposes more reliable alternatives.

Caption: Pressure calibration curves for different large volume presses at HPSTAR.

The team further introduces a nonlinear calibration curve fitting strategy based on the Voce hardening law, which better reflects the strain-hardening behavior of materials under high-pressure conditions and significantly improves calibration consistency across different devices and laboratories. The resulting methodology establishes a unified pressure reference for HPSTAR while also providing a standardized and broadly applicable calibration protocol for research groups worldwide operating large-volume press.

Link：https://doi.org/10.1063/5.0289378