LOW-TEMPERATURE THERMOMAGNETIC EFFECTS IN GRAPHITE

The low-temperature thermoelectric power (TEP) and the Nernst-Ettingshausen (NE) coefficient of graphite due to phonon drag are studied in the presence of a magnetic field H directed along the c axis and small enough for the quantum-mechanical character of the motion of the carriers to be negligible. Expressions for the TEP and the NE coefficient are obtained on the basis of the theory of Jay-Gerin and Maynard, in which the phonon-drag TEP of graphite in the absence of a magnetic field is linked with the Kohn screening anomaly. The results suggest a method by which information might be obtained about the strength of the electron- and hole-phonon coupling directly from experiment.