Used as a precursor in the synthesis of lanthanum-containing materials for optical coatings and phosphors in lighting and display technologies. Employed in catalyst preparation for petroleum refining and polymerization processes. Serves as a dopant in solid oxide fuel cells to enhance ionic conductivity. Applied in biological research as a tracer or enzyme inhibitor due to its ability to mimic calcium in cellular systems. Also utilized in water treatment for phosphate removal, helping to control eutrophication in aquatic environments.