Thermal conductivity of MgB2 in the superconducting state

Article

关键词: TRANSPORT-PROPERTIES;    HEAT;   

DOI  :  10.1103/PhysRevB.67.064505

来源: SCIE

【 摘 要 】

We present thermal conductivity measurements on very pure and dense bulk samples, as indicated by residual resistivity values as low as 0.5 muOmega cm 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 pi and sigma bands, which depend on the disorder in different way; namely, as the disorder increases, it reduces more effectively the relaxation times of pi than that of sigma bands, as suggested by a recent calculation [Mazin , Phys. Rev. Lett. 89, 107002 (2002)].

【 授权许可】

Free