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Updated: May 17, 2026
06:53
Magnetometric Characterization of Intermediates in the Solid-State Electrochemistry of Redox-Active Metal-Organic Frameworks
Published on: June 9, 2023
Specific heat versus field for LiFe(1-x)Cu(x)As
J S Kim1, G R Stewart, L Y Xing
1Department of Physics, University of Florida, Gainesville, FL 32611-8440, USA.
Summary
High-quality LiFeAs single crystals exhibit reduced residual electronic specific heat, indicating nodeless superconductivity. This finding contrasts with previous theories and highlights the importance of sample quality in iron superconductors.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Superconductivity
Background:
- LiFeAs belongs to a new class of iron superconductors with a bulk critical temperature (Tc) between 15-17 K.
- Previous studies suggested intrinsic states within the superconducting gap caused a finite residual electronic specific heat (γ(r)) in LiFeAs.
Purpose of the Study:
- To characterize the specific heat of high-quality LiFeAs single crystals.
- To investigate the influence of sample quality on the residual electronic specific heat.
- To explore the magnetic field dependence of specific heat in LiFeAs and compare it with nodal iron superconductors.
Main Methods:
- Self-flux growth technique for preparing LiFeAs single crystals.
- Specific heat measurements in zero and applied magnetic fields.
- Comparative analysis with LiFe(0.98)Cu(0.02)As and theoretical models.
Main Results:
- Significantly decreased residual electronic specific heat (γ(r)) was observed in high-quality LiFeAs, attributing it to sample quality rather than intrinsic states.
- Specific heat measurements in a magnetic field showed a non-linear dependence of the electronic density of states, consistent with nodeless superconductivity in multiband systems.
- Comparison with theoretical predictions for superconductors with two isotropic gaps and impurities supported nodeless behavior.
Conclusions:
- The residual electronic specific heat in LiFeAs is primarily a function of sample quality.
- LiFeAs exhibits nodeless superconductivity, serving as a model system for multiband, nodeless iron superconductors.
- Specific heat measurements in a magnetic field provide insights into the nature of the superconducting gaps and electronic structure.
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