Yttria coatings (Y2O3) on alumina (Al2O3) and titania (TiO2), manufactured by suspension plasma spraying, have been employed in a wide variety of applications. For example, they are used for anti-oxidation or anti-wear applications in semiconductors, where the sample of interest must resist contact with abrasive surfaces. Yttria is known for its low etch rate, but due to its high cost, the demand for high-purity ceramics as a substitute is increasing. Two micrographs below show ytrria coatings on alumina, with low plasma power density. 庫賽姆（COXEM）EM-30 Plus臺式 掃描電鏡