We report in our latest manuscript, published in Physical Review Research, the discovery of superconductivity in a previously unknown compound, Ta₄Rh₂C₁₋δ. This new material crystallizes in the η-carbide structure, adopting a cubic form with highly ordered atomic arrangements. Through a combination of magnetic susceptibility, resistivity, and specific heat measurements, we confirmed that Ta₄Rh₂C₁₋δ behaves as a type-II bulk superconductor.
The material becomes superconducting below 6.4 Kelvin, placing it in the category of low-temperature superconductors. However, what sets it apart is its unusually high upper critical magnetic field—measured at 17.4 Tesla—which significantly exceeds the theoretical Pauli limit of 11.9 Tesla predicted by conventional BCS (Bardeen-Cooper-Schrieffer) theory. This suggests that the superconducting state in Ta₄Rh₂C₁₋δ may involve unusual effects, making it a compelling subject for further theoretical and experimental study. Our findings add a new member to the family of superconducting materials.
