Plasma-Sprayed-Yttria Layers for Corrosion Resistance

Crucible corrosion in the growth of YBa2Cu3O7-x (YBCO) superconducting single crystals is one of the major obstacles in obtaining high-quality crystals. Both metallic and ceramic crucibles have shown significant corrosion that affects the size and properties of YBCO crystals. Plasma spraying has been successfully used to produce yttria coatings on alumina substrates. Yttria coatings with thicknesses between 30 and 100 μm have shown corrosion rates of 3 to 4 μm/h; these rates are 5 to 10 times lower than that of the alumina substrate.