Argon-neon binary diagram and ArNe₂ Laves phase.

Area of Science:

• High-pressure physics and chemistry
• Materials science
• Condensed matter physics

Background:

• Experimental studies of binary mixtures under extreme conditions are crucial for understanding material behavior.
• Argon (Ar) and neon (Ne) are noble gases with distinct atomic properties, making their mixtures under pressure an interesting subject.

Purpose of the Study:

• To investigate the phase behavior and structural properties of argon-neon mixtures at high pressures.
• To identify any novel stoichiometric compounds formed in the Ar-Ne system.
• To determine the stability and equation of state of observed phases.

Main Methods:

• High-pressure experiments were conducted on argon-neon mixtures.
• Structural characterization was performed to identify the crystal structure of any formed compounds.
• Equation of state measurements were taken up to 65 GPa.

Main Results:

• A stoichiometric compound with the composition ArNe2 was observed.
• This compound exhibits a hexagonal MgZn2 (Laves phase) structure.
• ArNe2 is stable up to at least 65 GPa and its equation of state aligns with an ideal Ar+2Ne mixture.
• The Ar-Ne phase diagram resembles hard sphere mixture predictions, indicating minimal electronic interactions.

Conclusions:

• The formation and stability of the ArNe2 Laves phase compound have been experimentally confirmed.
• The Ar-Ne system behaves like a mixture of hard spheres at high pressures, suggesting simple interatomic interactions.
• ArNe2 is identified as a potential quasihydrostatic pressure transmitting medium for moderate pressures.