X-ray photoelectron spectroscopy and static secondary ion mass spectroscopy study of activation mechanism of Zr–V low activation temperature nonevaporable getter films

Abstract

Thin films of the Zr–V alloy getter films were prepared on stainless steel substrates by magnetron sputtering. The getter activation behavior was investigated by x-ray photoelectron spectroscopy, static secondary ion mass spectroscopy, electron energy loss spectroscopy, and molecular beam technique. All measurements reflect the disappearance of the superficial oxide layer covering air exposed Zr–V surfaces via consecutive variation of the oxide stoichiometry during thermal activation. The adsorbed carbon is transformed simultaneously to carbides. During the activation heating hydrogen diffuses toward the surface forming surface hydride and hydroxyl groups. Although the detectable activation proceeds already at temperatures above 160 °C, the activation process is reasonably fast (a few hours) at higher temperatures (above 200 °C).