Used as a precursor in the synthesis of lanthanum-containing materials for catalysts, especially in petroleum refining for alkylation and isomerization processes. Employed in the production of specialty glasses and optical lenses due to its ability to improve refractive index and thermal stability. Applied in biological research as a tracer or blocking agent in electron microscopy and membrane studies. Also utilized in the preparation of luminescent materials and phosphors for lighting and display technologies. Serves as a source of lanthanum ions in solution for various inorganic and coordination chemistry applications.