Secondary electron emission and charging characteristics of ion-irradiated sapphire

Abstract Kinetic characteristics of sapphire (α-Al 2 O 3 ) single crystal irradiated by keV electrons are studied. We compare untreated sapphire with surfaces bombarded with Ar + ions and/or coated with a thin Al film. The electron emission yield and the charging characteristics for the untreated sapphire surface and for that bombarded by Ar + ions differ significantly. This difference is less when the sapphire sample is coated with a thin film of Al. We propose an explanation for the observed effects.