Structural and electronic effects in GdCu alloy.

Area of Science:

• Materials Science
• Condensed Matter Physics
• Solid State Chemistry

Background:

• Gadolinium Copper (GdCu) intermetallic compounds exhibit complex structural and electronic behaviors.
• Understanding phase stability and electronic structure is crucial for potential applications.

Purpose of the Study:

• To investigate the structural and electronic properties of GdCu.
• To analyze the effects of thermal cycling and surface preparation on phase stability and electronic structure.

Main Methods:

• X-ray diffraction (XRD) for structural analysis.
• Photoemission spectroscopy (PES) for electronic structure.
• Density Functional Theory (DFT) and DFT+U calculations for theoretical insights.

Main Results:

• As-prepared GdCu does not fully stabilize in the cubic CsCl phase at room temperature.
• Thermal hysteresis and strain-induced dislocations affect lattice parameters.
• Surface and bulk structures differ after thermal cycling, with cubic surface and orthorhombic FeB bulk phases.
• On-site Coulombic interactions in Gd 4f and Cu 3d orbitals are significant.
• Cu 4p states contribute to the electronic structure at the Fermi edge.
• Chemical potential shifts observed in PES studies after thermal cycling.

Conclusions:

• GdCu exhibits strain-dominated phase separation.
• Electronic structure is sensitive to structural changes and preparation methods.
• Results provide insights into systems with similar phase separation phenomena.