Used as a host material in phosphors for cathode ray tubes and fluorescent lamps due to its ability to emit red light when doped with europium. Commonly employed in solid-state lasers, especially in yttrium aluminum garnet (YAG) crystals, where it contributes to high thermal stability and optical clarity. Serves as a stabilizer for zirconia in producing strong, heat-resistant ceramics used in fuel cells and sensors. Applied in coatings for optical lenses to improve durability and reduce reflection. Also utilized in the electronics industry for gate dielectrics in thin-film transistors because of its high dielectric constant and compatibility with silicon. Investigated for use in medical imaging and cancer treatment when doped with rare earth elements for luminescent tagging and radiation shielding.