Chiang Mai Journal of Science

The role of phonon dragging at low temperatures have been included in the computer simulation of the electrical resistivities and the thermoelectric powers of transition metals. We come across with some of the new findings: The phonon drag resistivity r _g in the temperature region 1K£ T£ 5K follows power law r_{g µ} T⁵, while exponential decaying trend r_g = (1/T)exp(-b_g/T) above the temperature T=5K. We propose a new relation L = (mV_FT/ne²Z) exp(b/T) between phonon mean free path L and temperature T, which has been tested and found justified. Our new findings are also in case of phonon drag thermoelectric power Q_g for which a strong power law Q_gµ T³ is observed above to the temperature of Phonon dragging region, while in the phonon dragging region an exponential behaviour Q_g = (1/T)[k_g exp(-b_g/T)]^1/2 is found justified. The study concludes that after the characteristic temperature T=5K the phonons can participate in Umklopp process and they are frozen from Bose-Einstein distribution.