A LANTHANIDE LANTHOLOGY (.pdf) - Davidson Physics

YTTRIUM OXIDEThe widespread introduction of energy efficient fluoroescent lighting has become possible bythe use of phosphors emitting close to the three prime wavelengths of red, blue and green. Here thered comes from Eu:Y 2 O 3 . (The other colors also use lanthanide-containing materials.)[11]A recently introduced X-ray phosphor is yttrium tantalate, YTaO 4 . The garnet, YAG, is alsoused as the host for neodymium in Nd:YAG lasers. Most of these yttrium containing compoundsare made by high temperature reactions of yttria with the appropriate oxide, a fluxing agent beingbeneficial.A dispersion of fine particle yttria within an alloy substrate can increase the metal's strength.Such oxide dispersion strengthened (ODS) materials can be prepared by mechanical alloying, byball milling directly the metal powder and ≈1 % of a suitable small crystallite size yttrium oxidepowder. The resulting alloys show an enhanced resistance to deformation as a consequence of theY 2 O 3 particles blocking incipient cracks. Such nickel-based super alloys are used, for example, inthe hot sections of military jet engines as components subject to≈1250°C conditions.[11] Phosphors based on Rare-Earths, A New Era in Fluorescent Lighting, B.M.J.Smets, Mat.Chem.Phys.,1987, 16, 28357