The field of high-pressure experiments has seen a significant breakthrough with the development of a new sample configuration by an international team of scientists from various prestigious institutions. This innovative sample configuration has improved the reliability of equation of state measurements in a pressure regime previously unattainable in the diamond anvil cell. The implications of this advancement are vast, with the potential to conduct high-quality static equation-of-state measurements above 5 million atmospheres, reaching conditions akin to Neptune’s interior.
The Development of the Toroidal Diamond Anvil Cell
The Lawrence Livermore National Laboratory (LLNL) has been at the forefront of pushing the static pressure limit in condensed-matter sciences with the development of the toroidal diamond anvil cell. This revolutionary technology has paved the way for conducting static compression experiments to pressures exceeding 300 GPa. However, the next critical step in advancing high-pressure experiments was the enhancement of sample fabrication for more complex studies.
The new sample package developed by the international team of scientists addresses the challenges associated with static compression experiments at extremely high pressures. By providing an improved compression environment, the quality of equation of state data is significantly enhanced. This development represents a major achievement in optimizing static compression experiments at multi-megabar conditions.
Sample Package and Microfabrication Process
In the innovative sample package, the target material is embedded in a uniform capsule of soft metal, serving as a pressure-transmitting medium. This 10-step microfabrication process ensures that stress is uniformly distributed around the sample material, crucial for achieving reliable equation-of-state measurements. The small sample chamber, approximately 6 µm in diameter, allows for precise control and manipulation of the sample during high-pressure experiments.
Experimentation and Results
The experiments utilizing the LLNL-designed toroidal diamond anvil cell were conducted at Argonne National Laboratory Sector 16 HPCAT and at Deutsches Elektronen-Synchrotron PETRA-III. The team tested the methodology on molybdenum with a copper pressure-transmitting medium, demonstrating the versatility and robustness of the sample package. The implications of this advancement extend beyond the specific materials tested, with broad applications in physics, chemistry, and planetary science.
According to LLNL scientist Claire Zurkowski, this work represents just the beginning of sample-package microfabrication in the toroidal diamond anvil cell. The anticipation is that this sample-encapsulation method will propel static equation of state calibrations into the multi-megabar range, where data is currently limited. With the potential for reliable equation-of-state calibrations at pressures exceeding previous thresholds, the scientific community can look forward to groundbreaking discoveries in high-pressure experiments.
The collaborative effort of scientists from LLNL, Argonne National Laboratory, and Deutsches Elektronen-Synchrotron has yielded a remarkable advancement in high-pressure experimentation. The development of the new sample configuration and microfabrication process opens up a realm of possibilities for conducting reliable and precise measurements at unprecedented pressure conditions. This breakthrough marks a significant milestone in the field of high-pressure physics and sets the stage for future innovations and discoveries.
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