Abstract
While the phonon-drag effect can induce large Seebeck coefficients, it is associated with large mean free path phonons present in the vicinity of the maximum in temperature of the lattice thermal conductivity. In this paper, we initiate a new route by searching for the mutual drag between the electron and phonon-drag gases at the interface between two different media. In that respect, the temperature studies of the conductance and Seebeck coefficient of a model system consisting of an electrically conductive graphitic channel buried beneath the surface of a diamond crystal are shown. The observed behaviour is very similar to that of graphite, with a typical negative peak associated with the phonon-drag effect. Interestingly, this phonon-drag peak of the buried graphitic channel appears at a significantly higher temperature than that in pure graphite.