HOT-ELECTRON MAGNETOPHONON RESONANCE IN N-TYPE SI AT HIGH FIELDS UP TO 40-T

Hot electron magnetophonon resonances (MPR) in n-type Si were investigated at a temperature T=80 K in pulsed high magnetic fields up to 40 T. Although the oscillation profile is very complicated due to the overlap of several different intervalley MPR series, the assignment of each peak has become possible owing to the high resolution measurements in high magnetic fields. In the longitudinal magnetoresistance for B//(100) and B//(110) configuration, the dominant series of the observed MPR oscillation peaks M=2-19 (B//(100)) or N=3-19 (B//(110)) were assigned as the intervalley transitions from the excited states to the ground state of different valleys with the lighter electron mass by emitting a f-110 Sigma 3 phonon with a momentum of (2 pi h(cross)/a) (0.85, 0.85, 0). The electronic field dependence of the oscillation amplitude of each series and the damping factor were investigated in electric fields up to 300 V cm-1. The damping factor as a function of electric field was found to have a minimum in the warm electron range around 200 V cm-1.