Used as a key component in phosphors for color television screens and LED lighting, enabling bright red and green emissions. Employed in ceramics and glass to improve thermal stability and resistance to heat shock. Serves as a dopant in solid oxide fuel cells to enhance ionic conductivity. Applied in coatings for optical lenses due to its high refractive index and transparency in the visible and near-infrared range. Utilized in the production of superconductors and advanced electronic materials. Also explored in biomedical applications such as cancer treatment through yttrium-90 radioisotope generation.