Electron spin resonance in As‐doped Ge in a wide range of impurity concentration

Electron spin resonance of As donors in Ge has been investigated in the impurity concentration range 1.5 × 10 15 to 2 × 10 19 cm −3 at temperatures from 1.7 to 4.2 °K. Impurity conduction in the same samples has been studied for N As ≦ 2 × 10 17 cm −3 . It is shown that the line‐narrowing in the concentration range 2 × 10 17 cm −3 ≧ N As ≧ 4 × 10 16 cm −3 with H 0 ∥ [100] orientation cannot be due to the electron motion over impurity centres. Exchange‐narrowing due to the formation of clusters has been discussed. The reduction of angular dependence of the linewidth Δ H with increasing temperature is ascribed to transitions into excited states, by which contributions from different valleys to g ‐factor are averaged. For highly doped samples the rate of intervalley transitions has been estimated from the data on angular dependence of Δ H .