Thermal properties of MgB2: the effect of disorder on gap amplitudes and relaxation times of π and σ bands

We present thermal conductivity and specific heat measurements on MgB2 and Mg-AlB2 samples. Thermal properties have been analyzed by using a two-gap model in order to estimate the gap amplitudes, Δ(0)π and Δ(0)σ and the intra-band scattering rates, Γσσ and Γππ. Δ(0)σ rapidly decreases as a function of Al doping and disorder, while Δ(0)π is rather constant. Γσσ and Γππ are increased by disorder, being Γππ more affected than Γσσ