Mree

Due to the lanthanide contraction phenomenon, the REE are further divided into larger LREE (light Ln, La–Sm), medium MREE (Sm–Dy) and smaller HREE (heavy Ln, Tb–Lu and Y).

MREE possess unique properties that make them valuable for specific applications, including their use in phosphors for displays and lighting and in lasers for precise cutting and medical imaging.