Abstract
The superconductivity in the rare-earth transition-metal ternary borides (where and Y) has been investigated using muon-spin rotation and relaxation. Measurements made in zero field suggest that time-reversal symmetry is preserved upon entering the superconducting state in both materials; a small difference in depolarization is observed above and below the superconducting transition in both compounds, however, this has been attributed to quasistatic magnetic fluctuations. Transverse-field measurements of the flux-line lattice indicate that the superconductivity in both materials is fully gapped, with a conventional -wave pairing symmetry and BCS-like magnitudes for the zero-temperature gap energies. The electronic properties of the charge carriers in the superconducting state have been calculated, with effective masses and in the Lu and Y compounds, respectively, with superconducting carrier densities and . The materials have been classified according to the Uemura scheme for superconductivity, with values for of and , implying that the superconductivity may not be entirely conventional in nature.
1 More- Received 4 August 2015
- Revised 6 February 2018
DOI:https://doi.org/10.1103/PhysRevB.97.094506
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