Electronic Structure of Heteronuclear Cerium-Platinum Clusters

Area of Science:

• Materials Science
• Quantum Chemistry
• Solid-State Physics

Background:

• Cerium-platinum (Ce-Pt) intermetallic compounds display unique heavy fermion and magnetic instability properties.
• Small heterometallic Ce-Pt clusters offer localized insights into bulk phenomena but remain underexplored.

Purpose of the Study:

• Investigate the electronic structure and bonding characteristics of small mixed Ce-Pt clusters.
• Correlate cluster properties with phenomena observed in bulk Ce-Pt intermetallic materials.

Main Methods:

• Anion photoelectron spectroscopy was employed to probe the electronic states of Ce₂OPt^-, Ce₂Pt^-, and Ce₃Pt^- clusters.
• Density functional theory (DFT) calculations were performed to interpret experimental spectra and determine electronic configurations.

Main Results:

• Experimental spectra were well-reconciled with DFT calculations, revealing numerous closely spaced spin states.
• Cerium-platinum (Ce-Pt) bonds exhibit significant ionic character, with platinum in a -2 oxidation state.
• Cerium-platinum (Ce-Pt) bonds are stronger than cerium-cerium (Ce-Ce) bonds, and oxygen preferentially bonds to cerium.

Conclusions:

• The electronic structure of Ce-Pt clusters is sensitive to composition, influencing the relative energies of Ce 4f orbitals.
• Observed magnetic coupling (ferromagnetic and antiferromagnetic) in Ce-Pt clusters provides a foundation for understanding bulk magnetic behaviors.
• Findings have potential implications for the design and understanding of cerium-rich intermetallic materials.