I just quoting you from all different sources: 稀土元素 Rare Earth

镧(La)、铈(Ce)、镨(Pr)、钕(Nd)、钷(Pm)、钐(Sm)、铕(Eu)、钆(Gd)、铽(Tb)、镝(Dy)、钬(Ho)、铒(Er)、铥(Tm)、镱(Yb)、镥(Lu)以及与镧系的15个元素密切相关的两个元素——钪(Sc)和钇(Y)

轻稀土：镧（La)、铈(Ce)、镨(Pr)、钕(Nd)、钷(Pm)、钐(Sm)、铕(Eu)、钆(Gd)
重稀土：铽(Tb)、镝(Dy)、钬(Ho)、铒(Er)、铥(Tm)、镱(Yb)、镥(Lu)、钪(Sc)、钇(Y)

铈组：镧(La)、铈(Ce)、镨(Pr)、钕(Nd)、钷(Pm)、钐(Sm)
钇组：铕(Eu)、钆(Gd)、铽(Tb)、镝(Dy)、钬(Ho)、铒(Er)、铥(Tm)、镱(Yb)、钇(Y)

Z	名稱	英文名	應用範圍	Remark
21	钪 Sc	Scandium	铝钪合金（用于制造航天器械）、水银灯配件 Light Aluminium-scandium alloy for aerospace components, additive in Mercury-vapor lamps
39	钇 Y	Yttrium	钇鋁石榴石(YAG)、YBCO高溫超導体、钇铁石榴石(YIG) Yttrium-aluminum garnet (YAG) laser, Yttrium vanadate (YVO4) as host for europium in TV red phosphor YBCO high-temperature superconductors, yttrium iron garnet (YIG) microwave filters
57	镧 La	Lanthanum	高折射率玻璃、燧石、氫氣儲藏裝置、電池電極、相機鏡片、石油提煉液體催化過程(FCC)催化劑 High refractive index glass, flint, hydrogen storage, battery-electrodes, camera lenses, fluid catalytic cracking catalyst for oil refineries	Lynas,Gebeng
58	铈 Ce	Cerium	氧化剂、拋光粉、玻璃和瓷器的黃色染料、石油提煉液體催化過程(FCC)催化劑 Chemical oxidizing agent, polishing powder, yellow colors in glass and ceramics, catalyst for self-cleaning ovens, fluid catalytic cracking catalyst for oil refineries
59	镨 Pr	Praseodymium	稀土磁鐵、激光、玻璃和珐琅制品染料、燧石 Rare-earth magnets, lasers, core material for carbon arc lighting, colorant in glasses and enamels, additive in Didymium glass used in welding goggles ferrocerium firesteel (flint) products
60	钕 Nd	Neodymium	稀土磁鐵、激光、玻璃和瓷器的紫色燃料、陶瓷電容器 Rare-earth magnets, lasers, violet colors in glass and ceramics, ceramic capacitors
61	钷 Pm	Promethium	核電池 Nuclear batteries
62	钐 Sm	Samarium	稀土磁鐵、激光、中子捕獲裝置、激微波 Rare-earth magnets, lasers, neutron capture, masers
63	铕 Eu	Europium	紅色和藍色的荧光粉、激光、水銀燈部件 Red and blue phosphors, lasers, mercury-vapor lamps, NMR relaxation agent
64	钆 Gd	Gadolinium	稀土磁鐵、高折射指數玻璃、石榴石、激光、X射線管、電腦記憶體、中子捕獲裝置 Rare-earth magnets, high refractive index glass or garnets, lasers, X-ray tubes, computer memories, neutron capture, MRI contrast agent, NMR relaxation agent
65	铽 Tb	Terbium	綠色荧光粉、激光、荧光灯 Green phosphors, lasers, fluorescent lamps
66	镝 Dy	Dysprosium	稀土磁鐵、激光 Rare-earth magnets, lasers
67	钬 Ho	Holmium	激光 Lasers
68	铒 Er	Erbium	激光、钒鋼 Lasers, vanadium steel
69	铥 Tm	Thulium	便携式X射线机 Portable X-ray machines
70	镱 Yb	Ytterbium	紅外線激光、还原剂 Infrared lasers, chemical reducing agent
71	镥 Lu	Lutetium	高折射率玻璃 PET Scan detectors, high refractive index glass