Used in the production of high-strength permanent magnets when alloyed with other rare earth elements, enhancing performance in electric motors and wind turbine generators. Employed in fiber optic communications as a dopant in fiber amplifiers for signal boosting in the 1300 nm wavelength range. Applied in the manufacturing of specialized glass and ceramics, providing yellow-green coloration and UV absorption properties useful in protective eyewear and precision lenses. Utilized in research settings for catalytic studies and in the development of advanced materials with unique magnetic and electronic behaviors.