Used as a precursor in the synthesis of lanthanum-containing materials for optical coatings and phosphors in lighting and display technologies. Employed in catalysts for organic reactions, including polymerization and hydrocarbon transformations. Applied in research for developing solid oxide fuel cells due to its ionic conductivity when doped into ceramic matrices. Utilized in water treatment to reduce phosphate levels by forming insoluble lanthanum phosphate. Also investigated for use in medical applications, such as phosphate binders in dialysis treatments for kidney disease patients.