Pushing a pressure standard
A challenge for understanding systems at extreme conditions is knowing the exact pressure at which exotic behaviors occur. This situation is caused by the lack of an absolute pressure-density relationship of standard pressure calibrants. Fratanduono et al. conducted a series of dynamic compression observations on platinum and gold to establish a high-pressure scale for these metals up to terapascal conditions (see the Perpsective by Jeanloz). This work provides a robust calibration when using these standards in high-pressure devices such as diamond anvil cells.
Science, abh0364, this issue p. 1063; see also abi8015, p. 1037
Abstract
New techniques are advancing the frontier of high-pressure physics beyond 1 terapascal, leading to new discoveries and offering stringent tests for condensed-matter theory and advanced numerical methods. However, the ability to absolutely determine the pressure state remains challenging, and well-calibrated pressure-density reference materials are required. We conducted shockless dynamic compression experiments at the National Ignition Facility and the Z machine to obtain quasi-absolute, high-precision, pressure-density equation-of-state data for gold and platinum. We derived two experimentally constrained pressure standards to terapascal conditions. Establishing accurate experimental determinations of extreme pressure will facilitate better connections between experiments and theory, paving the way toward improving our understanding of material response to these extreme conditions.