Europium oxide is used for producing phosphor powder for color  televisions, three-color phosphor powder for lamps and used as activator  for X-ray intensifying screens. It can be used for producing colored lenses  and optical filters, also for magnetic bubble storage devices. Gadolinium oxide is used as an additive for samarium cobalt magnets.  Using gadolinium oxide and lanthanum together can help change  the vitrification area and improve the thermal stability of the glass.  Gadolinium oxide can also be used to make capacitors, x-ray intensifying  screens and so on. Terbium oxide is used as a green powder activator in phosphor powder.  

Used for magneto-optical storage materials. Used as terbium dysprosium  ferromagnetic magnetostriction alloy. Used for fuel injection systems,  fluid valve control, micro-positioning mechanical actuators, space  telescope adjustment mechanisms, aircraft wing adjusters and other  areas. Dysprosium oxide is used as additives for Nd-Fe-B permanent magnets  and as phosphor activator. It is a necessary metal material in producing  large magnetostrictive dysprosium metal terbium (Terfenol) alloy. It is  used as magneto-optical storage materials and as magnetic working  substances for magnetic refrigeration.