THE INFLUENCE OF ELECTRON IRRADIATION ON TENSORESISTANCE OF SINGLE CRYSTALS n-Ge

Abstract

Tensoresistance at the uniaxial pressure along the crystallographic directions [100], [110] and [111] for unirradiated and irradiated single crystals n-Ge by the flow of electrons F=5∙1015 el./cm2 , with the energy of 10 MeV, is investigated in the work. The presence of the tensoresistance for unirradiated single crystals n-Ge by the decrease of the average electrons mobility at the expense the deforming redistribution of electrons between the minima of conduction band of germanium with different mobility is explained. For the irradiated samples n-Ge the resistivity with the increasing uniaxial pressure has decreased for all crystallographic directions. For a more detailed study of the tensoresistance effect of the irradiated single crystals n-Ge, the measurements of tenso-Hall effect also have been conducted. The anomalous dependences of the Hall constant on uniaxial pressure along the crystallographic directions [100], [110] and [111] were obtained. With an analysis of these dependencies concluded that the observed tensoresistance effect for irradiated single crystals n-Ge, mainly, explains by the mechanisms of the mixed conductivity: by the changes of electrons concentration in the conduction band and holes in the valence band by changing the ionization energy of deep level + 0,27 EV eV at the uniaxial pressure. The investigations of tensoresistance and tenso-Hall effect at room temperature were carried out. For irradiated single crystals of n-Ge, at the uniaxial pressure P>0,25 GPa along the crystallographic direction [100], the linear dependence of the tensoresistance was obtained. Such feature of the tensoresistance, unlike the unirradiated samples, can find a practical use for designing based on irradiated n-Ge the pressure sensors for the control of high uniaxial pressure.