Specific heat of FeSe: Two gaps with different anisotropy in superconducting state
| Autor: | A. V. Sadakov, A.R. Prishchepa, Dmitriy A. Chareev, A.V. Muratov, V. M. Pudalov, G.S. Epifanova, S. Yu. Gavrilkin |
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| Rok vydání: | 2018 |
| Předmět: |
Superconductivity
Materials science Condensed matter physics Transition temperature Isotropy 02 engineering and technology Atmospheric temperature range 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Electronic Optical and Magnetic Materials Magnetic field Amplitude Electrical resistivity and conductivity 0103 physical sciences Electrical and Electronic Engineering 010306 general physics 0210 nano-technology Anisotropy |
| Zdroj: | Physica B: Condensed Matter. 536:785-789 |
| ISSN: | 0921-4526 |
| DOI: | 10.1016/j.physb.2017.10.041 |
| Popis: | We present detailed study of specific heat of FeSe single crystals with critical temperature T c = 8.45 K at 0.4 − 200 K in magnetic fields 0 − 9 T. Analysis of the electronic specific heat at low temperatures shows the coexistence of isotropic s-wave gap and strongly anisotropic extended s-wave gap without nodes. It was found two possibilities of superconducting gap parameters which give equally description of experimental data: (i) two gaps with approximately equal amplitudes and weight contribution to specific heat: isotropic Δ 1 = 1.7 meV ( 2 Δ 1 / k B T c =4.7) and anisotropic gap with the amplitude Δ 2 max = 1.8 meV ( 2 Δ 2 max / k B T c =4.9 and anisotropy parameter m = 0.85 ); (ii) two gaps with substantially different values: isotropic large gap Δ 1 = 1.65 meV ( 2 Δ 1 / k B T c = 4.52 ) and anisotropic small gap Δ 2 max = 0.75 meV ( 2 Δ 2 max / k B T c = 2 ) with anisotropy parameter m = 0.71 . These results are confirmed by the field behavior of the residual electronic specific heat γ r . |
| Databáze: | OpenAIRE |
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