Extended X-ray absorption fine structure of dynamically-compressed copper up to 1 terapascal

Area of Science:

• Materials Science
• High-Pressure Physics
• Planetary Science

Background:

• Large laser facilities enable material characterization at extreme pressures, simulating planetary cores.
• Accurate temperature measurements under such conditions are challenging and often rely on models.
• Lack of direct diagnostics limits understanding of material behavior at high pressures.

Purpose of the Study:

• To report on temperature, density, pressure, and local structure of copper at extreme pressures.
• To develop and apply novel diagnostics for material characterization under high-pressure conditions.
• To investigate the influence of experimental environment on material properties at terapascal pressures.

Main Methods:

• Utilized large laser facilities for material compression.
• Employed extended X-ray absorption fine structure (EXAFS) for material analysis.
• Applied velocimetry techniques for pressure and state determination.
• Achieved pressures up to 1 Terapascal, a new record for EXAFS.

Main Results:

• Determined temperature, density, pressure, and local structure of copper up to 1 Terapascal.
• Nearly doubled the highest pressure at which EXAFS has been reported.
• Observed unexpectedly high copper temperatures when adjacent to diamond layers.
• Demonstrated significant influence of the sample environment on material thermal state.

Conclusions:

• Direct measurement of material properties at extreme pressures is now feasible.
• The experimental environment, specifically diamond anvils, significantly impacts material temperature.
• Findings provide crucial data for refining models and experimental designs in high-pressure research.
• This work advances understanding of materials under conditions relevant to planetary cores.