Yttrium(III) nitrate tetrahydrate is widely used in the production of phosphors, particularly for cathode ray tubes and LEDs, where it enhances brightness and color quality. It serves as a precursor in the synthesis of yttrium oxide, which is crucial for manufacturing high-performance ceramics and superconductors. In the field of catalysis, it is employed to improve the efficiency of chemical reactions, especially in petroleum refining and organic synthesis. Additionally, it is utilized in the preparation of specialty glasses and optical materials due to its ability to modify refractive indices and thermal properties. Its role in research and development includes applications in material science for creating advanced composites and coatings.