Fabrication and properties of ceramic coatings for CTR liquid blanket by sputtering method

Development of ceramic coating is one of the most important subjects in fusion-reactor liquid-metal blanket R&D. Al2O3 and AlN are candidate materials for ceramic coatings because of their high electrical resistivity and high thermodynamic stability. In this study, Al2O3 and AlN coatings were fabricated by the RF sputtering method and their properties were investigated. The prepared Al2O3 coating was amorphous, and it had high electrical resistance with no porous structure. On the other hand, the resistance of the prepared AlN coating changed in the range of 10 orders of magnitude depending on the composition of the working gas. This is presumably derived from the nitrogen deficiency in the product.