Electron-induced secondary electron emission of aluminum alloy processed via the combination of alodine treatment and carbon film deposition

Abstract

• A porous chromate film is formed on the Al alloy via alodine treatment. • Secondary electron emission (SEE) of Al alloy is suppressed via alodine treatment. • SEE of alodine-treated Al alloy is further suppressed via carbon film deposition. • This SEE suppression is beneficial from the porous structure and sp 2 carbons. Relatively strong electron-induced secondary electron emission (SEE) of ordinary aluminum (Al) alloy limits its applications in high-power microwave devices. In this work, a combination strategy of alodine treatment and amorphous carbon (a-C) film deposition for Al alloy was proposed to achieve a goal of SEE suppression. According to the experimental results, it can be found both alodine treatment and a-C film deposition are advantageous to reducing secondary electron yield (SEY) of Al alloy. Moreover, the combination of these two surface treatments can further suppress the SEE of Al alloy due to the superposition effect of nanoscale porous structure and larger numbers of sp 2 carbon bonds. Compared with those of the untreated one, the SEY peak value, first crossover energy and second crossover energy of the Al alloy processed via the combined surface treatment change from 1.7, 25 eV and 2900 eV to 1.08, 150 eV and 650 eV, respectively.