Equation of state measurements in high-pressure regimes are crucial in understanding the behavior of materials under extreme conditions. A recent paper published in the Journal of Applied Physics highlights the development of a new sample configuration by an international team of scientists from Lawrence Livermore National Laboratory (LLNL), Argonne National Laboratory, and Deutsches Elektronen-Synchrotron. This innovative sample package aims to improve the reliability of equation of state measurements in pressure regimes previously unattainable in the diamond anvil cell.
Static compression experiments above 300 GPa pose significant challenges due to the limited ideal compression environment. The compression environment is often not optimal, leading to a decrease in the quality of equation of state data. The new sample configuration developed by the team addresses this issue by providing an improved compression environment, enhancing the quality of equation of state measurements. This development is a significant advancement in the field of static compression experiments.
The LLNL-designed toroidal diamond anvil cell has been instrumental in pushing the static pressure limit in condensed-matter sciences. The toroidal diamond anvil cell is capable of reaching pressures above 300 GPa, with a sample chamber approximately 20 times smaller than the width of a human hair. This small sample chamber allows for precise and controlled experiments at extreme pressure conditions.
The sample package developed by the team involves a 10-step microfabrication process where the target material is embedded in a uniform capsule of soft metal. This soft metal capsule serves as a pressure-transmitting medium, ensuring that stress is uniformly distributed around the sample material during compression. The use of this sample package in the diamond anvil cell enables reliable equation of state measurements, even on a micron scale.
The experiments were conducted at Argonne National Laboratory Sector 16 HPCAT and Deutsches Elektronen-Synchrotron PETRA-III. The scientists tested the methodology using molybdenum with a copper pressure-transmitting medium. The results of the experiments demonstrated the effectiveness of the sample package in improving equation of state data quality. The team anticipates that this sample-encapsulation method will push static equation of state calibrations into the multi-megabar range, where data is currently limited.
The development of the new sample configuration for equation of state measurements represents a significant breakthrough in the field of high-pressure physics. The improved reliability and quality of the data obtained using this new sample package open doors for further research and experimentation in physics, chemistry, and planetary science materials. This work paves the way for optimized static compression experiments at multi-megabar conditions, providing valuable insights into material behavior under extreme pressure regimes.
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