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arXiv · 1407.6680

Physical properties of noncentrosymmetric superconductor LaIrSi3: A μSR study

V. K. Anand·D. Britz·A. Bhattacharyya·D. T. Adroja·A. D. Hillier·A. M. Strydom·W. Kockelmann·B. D. Rainford·K. A. McEwen
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Abstract

The results of heat capacity C_p(T, H) and electrical resistivity ρ(T,H) measurements down to 0.35 K as well as muon spin relaxation and rotation (\muSR) measurements on a noncentrosymmetric superconductor LaIrSi3 are presented. Powder neutron diffraction confirmed the reported noncentrosymmetric body-centered tetragonal BaNiSn3-type structure (space group I4\,mm) of LaIrSi3. The bulk superconductivity is observed below T_c = 0.72(1) K. The intrinsic ΔC_e/γ_n T_c = 1.09(3) is significantly smaller than the BCS value of 1.43, and this reduction is accounted by the α-model of BCS superconductivity. The analysis of the superconducting state C_e(T) data by the single-band α-model indicates a moderately anisotropic order parameter with the s-wave gap Δ(0)/k_B T_c = 1.54(2) which is lower than the BCS value of 1.764. Our estimates of various normal and superconducting state parameters indicate a weakly coupled electron-phonon driven type-I s-wave superconductivity in LaIrSi3. The \muSR results also confirm the conventional type-I superconductivity in LaIrSi3 with a preserved time reversal symmetry and hence a singlet pairing superconducting ground state.

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V. K. Anand, D. Britz, A. Bhattacharyya, D. T. Adroja, A. D. Hillier, A. M. Strydom, W. Kockelmann, B. D. Rainford, K. A. McEwen. 2014-07-24. Physical properties of noncentrosymmetric superconductor LaIrSi3: A μSR study. https://doi.org/10.1103/physrevb.90.014513

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