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Updated: Jun 27, 2025
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Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
Published on: June 7, 2018
8.5K
Charge fluctuations in the intermediate-valence ground state of SmCoIn5
David W Tam1, Nicola Colonna1,2, Neeraj Kumar3
1Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institut, 5232 Villigen, Switzerland.
Communications Physics
|April 26, 2024
Summary
Replacing cerium with samarium in heavy fermion materials reveals that crystal electric fields control f-electron delocalization. This finding is crucial for understanding unconventional superconductivity and quantum critical points in rare earth compounds.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Quantum Materials
Background:
- Heavy fermion materials, crucial for unconventional superconductivity, rely on the delocalization of f electrons into a Kondo lattice.
- Understanding the microscopic mechanisms governing heavy band formation is key to designing novel superconducting materials.
- Cerium (Ce)-based compounds like CeCoIn5 are prime examples, but exploring alternatives is vital for broader insights.
Purpose of the Study:
- To investigate the role of crystal electric fields and Coulomb repulsion in heavy band formation using samarium (Sm) instead of cerium (Ce).
- To explore the impact of multiple f electrons on the ground state and delocalization behavior in SmCoIn5.
- To clarify the influence of charge fluctuations in "115" materials near a heavy fermion quantum critical point.
Main Methods:
- Substitution of Ce3+ with Sm3+ in the CeCoIn5 structure to create SmCoIn5.
- Analysis of the resulting ground state, considering crystal electric field and on-site Coulomb repulsion effects.
- Investigation of temperature-induced valence crossover and f-hole delocalization using experimental probes (implied).
Main Results:
- SmCoIn5 exhibits a Γ7 ground state, analogous to CeCoIn5, due to the interplay of crystal electric field and Coulomb repulsion.
- A temperature-induced valence crossover occurs in SmCoIn5 below approximately 60 K, indicating a Kondo scenario.
- Increased delocalization of f holes is observed below 60 K, demonstrating the crystal field's dominance in tuning delocalization.
Conclusions:
- Crystal electric fields are the primary factor controlling f-electron delocalization efficiency near heavy fermion quantum critical points, even with multiple f electrons.
- Charge fluctuations play a significant and general role in establishing the ground state properties of "115" materials.
- This study provides a new perspective on heavy fermion physics by utilizing Sm, offering insights into unconventional superconductivity mechanisms.
Keywords:
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