Penetration of Electrons in Aluminum Oxide Films

Abstract

The practical range of low-energy electrons in thin ${\mathrm{Al}}_{2}$${\mathrm{O}}_{3}$ films has been measured. Films ranging in thickness from 85 to 5000 A were investigated. Results are in close agreement with the predictions of Bethe and the results obtained by Hoffman for 1000-3000 A ${\mathrm{Al}}_{2}$${\mathrm{O}}_{3}$ films. The practical range-energy relation obtained was found to be $R=0.0115{E}^{1.35}$, where $R$ is expressed in mg/${\mathrm{cm}}^{2}$ and $E$ in kev.