The field of high-pressure physics has seen a significant breakthrough with the development of a new sample configuration by an international team of scientists. This innovation, recently published in the Journal of Applied Physics, aims to improve the reliability of equation of state measurements in a pressure regime previously unattainable in the diamond anvil cell. This new development opens the door to conducting high-quality static equation-of-state measurements above 5 million atmospheres, equivalent to the interior conditions of Neptune.
The toroidal diamond anvil cell, developed by Lawrence Livermore National Laboratory (LLNL), has been instrumental in pushing the static pressure limit in condensed matter sciences. However, the next critical step was enhancing sample fabrication to enable more complex experiments. Static compression experiments at pressures exceeding 300 GPa pose significant challenges, with the compression environment often falling short of ideal conditions.
The newly developed sample package addresses these challenges by introducing an improved compression environment, resulting in higher-quality equation of state data. By using a ten-step microfabrication process, the scientists embedded the target material in a soft metal capsule within a 6 μm diameter sample chamber. This ultra-small sample chamber, approximately 20 times smaller than the width of a human hair, allows for precise control and uniform stress distribution around the sample material.
In high-pressure experiments, achieving a reliable equation of state measurement is crucial for understanding the behavior of materials under extreme conditions. The soft metal capsule serves as a pressure-transmitting medium, ensuring that stress is uniformly redistributed around the sample material when compressed along a single axis by the anvils in the diamond-anvil cell. This innovative sample packaging technique has the potential to revolutionize static compression experiments at multi-megabar conditions.
The successful application of this sample packaging method on molybdenum with a copper pressure-transmitting medium opens up possibilities for its broad utilization across different materials and disciplines. LLNL scientist Claire Zurkowski, the first author of the paper, envisions that this breakthrough is just the beginning of sample-package microfabrication in the toroidal diamond anvil cell. By extending static equation of state calibrations into the multi-megabar range, this approach has the power to advance research in physics, chemistry, and planetary science.
The development of a novel sample configuration for high-pressure experiments represents a significant advancement in the field of static compression. By combining the capabilities of the toroidal diamond anvil cell with sophisticated sample packaging techniques, scientists have unlocked the potential to explore conditions previously inaccessible. This breakthrough marks a crucial step towards enhancing our understanding of material behavior at extreme pressures and temperatures, paving the way for groundbreaking discoveries in various scientific disciplines.