Nernst‐Ettingshausen and Seebeck Effect of Pure and Electron‐Irradiated Tellurium at Low Temperatures

For the first time experimental data of the Nernst‐Ettingshausen effect at low temperatures in tellurium are reported. Measurements of resistivity, Hall coefficient, Seebeck coefficient, and Nernst‐Ettingshausen coefficient on the same sample allow to deduce directly the scattering exponent r, which characterizes the energy dependence of the relaxation time τ. The results clearly reveal a strong anisotropy in the scattering factor r. This is explained by the presence of dislocations. Irradiations with 1 MeV electrons at low temperatures confirm earlier results on the recovery stages I and II in tellurium. It is demonstrated that the Nernst‐Ettingshausen effect is a very useful tool to decide whether recombination or only rearrangement of radiation induced defects occurs during sample recovery.