Determination of the Effective Scattering Mechanism Parameter of Electron Transport Theory

For Corbino disk geometry, the variation of thermoelectric power $\alpha$ with magnetic-field strength $H$ is a strong function of the scattering and a weak function of the Fermi level. The zero magnetic-field thermo-electric power is a strong function of the Fermi level and a weak function of the scattering. Thus, measurements of $\frac{\Delta \alpha }{\alpha \mathrm{}\left(0\right)\mathrm{}}$ versus $H$ and $\alpha \mathrm{}\left(0\right)\mathrm{}$ at a particular impurity concentration and temperature should yield a scattering parameter and a Fermi level separately. The transport equation for $\frac{\Delta \alpha }{\alpha \mathrm{}\left(0\right)\mathrm{}}$ has been derived for the case of a simple spherically symmetric energy band, arbitrary scattering, exact statistics, and Corbino disk geometry. The thermoelectric power increased 55% as the magnetic field increased to 22 kgauss for mercuric selenide. Although there is some evidence which indicates that the simple band form does not occur in HgSe, a preliminary comparison of theory and experiment showed satisfactory agreement.