Process Optimization of Er2O3 Coating by Reactive Magnetron Sputtering for DEMO-Relevant Blanket Modules

AbstractIndia has proposed to develop and test the Lead-Lithium–cooled Ceramic Breeder Test Blanket Module (In-LLCB-TBM) in ITER. This concept, unlike some others, may need a high-performance ceramic coating on the inner wall to meet dual requirements such as high insulation to mitigate magnetohydrodynamic effects and a tritium permeation barrier to avoid tritium in the structural material. We deposit Er2O3 coatings using a direct-current magnetron reactive sputter deposition technique. As part of optimizing the coating from the application point of view, we carried out a series of deposition experiments. These included investigating the effects of substrate temperature in the range 165°C to 360°C, the effects of postannealing, and the effects of oxygen-to-argon gas flow ratio, keeping all other process parameters constant. Primarily, a densely packed film is required to grow in the most stable cubic crystal structure, with very high resistivity, in the range of gigaohm-centimeters to teraohm-centimeters....