Tritium-permeation-barrier properties of erbium oxide (TPB) coating on CLAM steel

摘要

Erbium oxide (Er2O3) coatings are considered as the candidate for tritium permeation barrier (TPB) because of its low permeation reduced ratio. The enhanced adhesion between TPB layer and metal substrate is one of the key issues for the high reliability. In this work, erbium coatings were firstly prepared by radio frequency (RF) magnetron sputtering and then annealed to generate Er2O3 TPB coatings, accompanied with Er2Fe17 due to inter diffusion between Er and steel substrates. The coatings are compact and smooth if the annealing temperature is above 873 K. The samples are insulator at room temperature, and meet the requirement of TPB in blanket. The adhesion of coatings could be improved with elevating annealing temperature. According to the AES profile, a thickness controllable TPB multi-layered model of Er2O3/Er2O3+Er/Er/Er2Fe17/Fe is proposed.