05 October 1984
Vol 226, Issue 4670

About The Cover

Lead-iron phosphate glass (disk at center) is surrounded by lead phosphate glass wedges doped with about 1 mole percent of various optically active metal ions. The blue glass wedge is doped with cobalt, and (in a clockwise direction) the other dopants are nickel, samarium, copper, erbium, praseodymium, and neodymium. Lead-iron phosphate glass is a promising new host for the disposal of nuclear wastes. See page 45. [Samples prepared by B. C. Sales and L. A. Boatner; photograph by Bill Norris, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831]