It is used in nuclear reactors to manufacture control rods and is also a component of many magnetic alloys, for example with iron and chromium. It is needed as an MRI contrast agent for pharmaceutical diagnostics as well as for ceramic spray powders.
Gadolinium is used in the manufacture of special optical glass as well as in the production of phosphors and fluorescent powders that make radar screens glow green. In the form of gallium gadolinium garnet, it is used to manufacture optical components for laser devices, for example, and as a substrate material for magneto-optical memories.