Electrical nonlinearity of magnetodynamic nature in metals at high levels of energy dissipation

Abstract

In cryoconductors of Corbino geometry made from uncompensated metals the phenomenon of nonlinear coupling between electrical field and current density is observed at rather low density of radial current. Nonlinearity is caused by a magnetic field of azimuthal drift of carriers due to the Lorentz force in an external magnetic field of the solenoid. In this report the results of investigation of the nonlinear phenomena in aluminum disks at different levels of dissipation of electrical energy are presented. The level of dissipation substantially redefines the thermal condition of system. Research was carried out by a method of registration of current-voltage characteristics in a preset current mode. Samples had different surface-volume ratios at a variation of their geometrical farms. In particular the samples in the form of a disk with a constant height along radius and also with a hyperbolic axial section are used. Measurements have been carried out in magnetic fields up to 8 T at loading current density up to 800 A/cm2. The opportunity of existence of the asymptotic steady temperature-electric domain structure is discussed. Domains result in stabilization of current-voltage characteristic through the mechanism of non-local heat removal.