Possibility of detecting phonon drag due to an electronic heat current

The influence of the non-equilibrium distribution of the electrons on the thermal conductivity of the lattice lambda/sub g/ has been theoretically investigated in the literature. It was found that the effect is very slight and leads to corrections to the calculated lambda/sub g/ of order kT/μ, where μ is the chemical potential of the electrons, and thus was thought to be unobservable. A simple physical picture is presented showing how, in favorable circumstances, the Righi-Leduc effect may be used to magnify the non-equilibrium effects by factors of the order of 104 which should lead to observable changes of lambda/sub g/. Experimental results on tungsten and cadmium are briefly reported