Seminars Archive

A novel route to extreme vacua: the non-evaporable getter thin film coatings

Abstract
Vacuum chambers sputter-coated with a thin film (~ 1.5 m) of a getter material, and subsequently exposed to ambient air, have been found to recover a pumping action after "in-situ" bakeout. Coatings of Ti, Hf, Zr have been initially produced and studied, followed by their binary equiatomic alloys TiHf, HfZr, TiZr. All these coatings display activation at temperatures lower than 400C, as observed by means of X-ray Photoelectron Spectroscopy surface analysis, Electron Stimulated Desorption (ESD), pumping speed and ultimate pressure measurements. The lowest activation onset temperature, about 200C, has been measured for the equiatomic TiZr alloy. A further activation temperature decrease has been achieved for TiZr based ternary alloys/compounds, of which the investigation is currently in progress.