Chemical states and deuterium retention behavior of vacuum plasma sprayed tungsten coatings

Tungsten (W) coatings were prepared using vacuum plasma spraying (VPS) technology and then the chemical states and retention behaviors of deuterium in VPS-W coatings were analyzed by X-ray photoelectron spectroscopy (XPS) and thermal desorption spectroscopy (TDS). The results showed that chemical reacted oxygen (W–O bonds) and chemisorbed oxygen (O–O bonds) existed both on the surface and interior of tungsten coatings. Oxygen was chemically sputtered during D 2 + implantation. Two deuterium desorption stages at the temperature ranges around 300–700 K and 800–1150 K were observed for tungsten coatings. The retention behavior of deuterium in tungsten coatings was greatly different from that of bulk tungsten, which was related to the existence of oxygen.