2002/10/08 by M. Putti, V. Braccini, E. Galleani d'Agliano +7
Materials Science · Physics and Astronomy · #Anisotropy #Condensed matter physics #Electrical resistivity and conductivity #Omega #Optics #Phonon #Physics #Physics of Superconductivity and Magnetism #Quantum mechanics #Relaxation (psychology) #Residual resistivity #Scattering #Superconductivity #Superconductivity in MgB2 and Alloys #Thermal Expansion and Ionic Conductivity #Thermal conductivity #Thermodynamics #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.67.064505
published as Phis. Rev. B 67 (2003) 064505 · 12 pages, 5 figures
arxiv created 2002/10/08 · openalex publication_date 2003/02/25 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/15
We present thermal conductivity measurements on very pure and dense bulk samples, as indicated by residual resistivity values as low as 0.5\ensuremathμ\ensuremathΩcm and thermal conductivity values higher than 200 W/mK. In the normal state we found that the Wiedemann-Franz law, in its generalized form, works well suggesting that phonons do not contribute to the heat transport. The thermal conductivity in the superconducting state has been analyzed by using a two-gap model. Thanks to the large gap anisotropy we were able to evaluate quantitatively intraband scattering relaxation times of \ensuremathπ and \ensuremathσ bands, which depend on the disorder in different way; namely, as the disorder increases, it reduces more effectively the relaxation times of \ensuremathπ than that of \ensuremathσ bands, as suggested by a recent calculation [Mazin et al., Phys. Rev. Lett. 89, 107002 (2002)].