Phonon Drag and Phonon Interactions inn-InSb

The experimental results of phonon-drag thermoelectric power of $n$-InSb are analyzed to obtain information about electron-phonon and phonon-phonon interactions. We find that for temperatures greater than 6°K, the piezoelectric mode of electron scattering is negligible as compared to the deformation potential type of scattering. A value of 8.25 eV is found for the deformation-potential constant. The relaxation time of long-wavelength acoustical phonons is given by ${\tau }_q\mathrm{}\left(T\right)=4.4\mathrm{}\times \frac{{10}^3}{q{T}^3}$ for temperatures $\tau \le 40°$K. The data also indicate that inelasticity of electron-phonon collisions as well as collision broadening of the electron energy levels are the dominant "cutoff" mechanisms involved in the quantum theory of magnetoresistance; the first dominates in relatively low fields, while the latter takes over for fields greater than 60 kG.