Bengus S. Nonstationary processes in bismuth in the phonon generation mode

Object – galvanomagnetic properties of bismuth under supersonic drift of charge carriers. Goal – clarification of the energy distribution between both electron and nonequilibrium phonon systems under Esaki effect conditions. Investigation of nonstationary processes connected with the relaxation of nonequilibrium phonons. Method – pulse methodic of galvanomagnetic measurements. Results, novelty – the new method is proposed to study of acoustoelectric properties of materials in which a supersonic drift of charge carriers is possible; the phonon-electron relaxation path in bismuth has been determined for the generated phonons; the nonlinear galvanothermomagnetic effect has been found; the energy is determined which comes to nonequilibrium phonon system from electron system and direct connection of IVC nonlinearity of bismuth with phonon generation is experimentally confirmed; the new reliable method of an excitation of acoustoelectric oscillations is developed, and for the first time it is shown experimentally that a phonon-electron relaxation of nonequilibrium acoustic pulse of acoustoelectric domains is the necessary condition for this nonstationary process. Employment – fundamental science, investigation of materials for acoustoelectronics, low temperature solid state refrigerators, cryoelectronics