sporiding to A10l’~R , indicates that a t this high temperature they had actually formed this phase without rccognizirig it.
Acknowledgment. This work was supported under A.E.C. Contract No, At(:30-1)-2.?41 with the I’ennsylvariia State University. The author gratefully ac-
knowledges the courtesy of the Satiorial Rurcau of Standards for the use of the mass spcctrotneter in this investigation. He is also indebted to Dr. .J. Hfinienko for his help arid interest in the mass spcctronietric work and to A h 0 . C. Shopay, AIiss E. ‘2. Hcrschbergcr, and A h . I
