Low-temperature magnetothermoelectric power of aluminum

Measurements of the low-temperature magnetothermoelectric power of aluminum and a number of aluminum alloys show that the electron-diffusion component S_d increases and then saturates with increasing magnetic field. The difference ΔS_d between the high- and zero-field values of S_d is observed to be independent of the type of impurity in the aluminum and has the value (2.2±0.2)T×10^-8V/K. These observations are interpreted in terms of a realistic semiclassical analysis of the thermopower. This treatment gives an excellent account of the qualitative behavior of the thermopower in a magnetic field but yields a value of ΔS_d which is 30% lower than the observed value. Possible reasons for this descrepency are discussed.