CaCu_1.424Fe_0.576Si₂

Area of Science:

• Materials Science
• Solid State Chemistry
• Crystallography

Background:

• Quasicrystals and related intermetallic phases are of significant interest due to their unique properties.
• Previous research has identified related Ca-Cu-Si and Ca-Fe-Si phases with known crystal structures.

Purpose of the Study:

• To synthesize and characterize a new phase formed during high-pressure sintering of an Si-rich quasicrystal prealloy.
• To determine the crystal structure and atomic arrangement of the newly obtained phase.

Main Methods:

• High-pressure sintering of a Si61Cu30Ca7Fe2 prealloy.
• X-ray diffraction analysis to determine the crystal structure and lattice parameters.
• Refinement of site occupancy factors for co-occupying atoms.

Main Results:

• A new phase, CaCu1.424Fe0.576Si2, was successfully synthesized.
• The phase crystallizes in the I4/mmm space group with lattice parameters a = b = 4.041 Å and c = 10.010 Å.
• Copper and iron atoms exhibit co-occupancy on specific crystallographic sites with a ratio of approximately 0.71:0.29.

Conclusions:

• The synthesized CaCuFeSi phase is isotypic with known CaCu2Si2 and CaFe2Si2 compounds.
• The co-occupancy of Cu and Fe atoms is a key feature of this new phase.
• This finding contributes to the understanding of phase formation in Si-rich transition metal systems under high pressure.