Improvement in the accuracy of determining impurity compensation in pure weakly compensated germanium from breakdown-field strength

It is shown that measurement of the electric-breakdown field $E_{\operatorname{br}}$ in a classically high magnetic field $(H)$ at $T$ = 4.2 K makes it possible to determine the value of the degree of compensation $K$ in pure germanium with $K<$ 50% much more precisely than at $H$ = 0. The parameter $S=E_{\operatorname{br}}/H$ is introduced and its dependence $S = f(K)$ is calculated; the obtained curve makes it possible to determine $K$ if $H$ and $E_{\operatorname{br}}$ are known. To decrease the resistance of the samples, it is recommended that measurements be carried out under “impurity” illumination. It is shown that the value of $E_{\operatorname{br}}$ is invariable at low intensities of such excitation.