TEST OF A BINARY MIXTURE MODEL FOR THE THERMOELECTRIC-POWER OF ION-BOMBARDED NBN-FILMS

Sputtered NbN-films are ion irradiated at 295 K with 350 keV Ne+-ions thereby producing radiation damage and the corresponding changes of the temperature-dependent electrical resistivity rho(T) and the thermopower S(T) are determined within 16 K less-than-or-equal-to T less-than-or-equal-to 295 K ion fluences PHI less-than-or-equal-to 2.5.10(15) cm-2. Regarding the bombarded film as a binary mixture of grains with defect densities below or above a certain threshold value, the above measurements allow to test a binary mixture model for the thermopower. Excellent agreement between theory and experiment is found, though the irradiation-induced resistivity changes do not obey Matthiessen's rule.