Abstract: Thick, finely-grained films of cermets are fabricated using conventional techniques of sputtering the ceramic and the metal onto a substrate. The cermet is then subjected to differential sputtering in which the metal is sputtered away faster than the ceramic to leave a ceramic-rich surface layer having excellent secondary-electron-emission properties for low-energy incident electrons. Typical of such cermets are MgO/Au, MgO/Pt and MgO/Ag. The presence of metallic particles in the bulk of the films and the small size of the ceramic particles greatly reduce surface charging while allowing the emitter film to be made thick enough to have a long operating life under adverse device conditions.

Abstract: A method for the separation of a light reactive metal (e.g., zirconium) from a heavy reactive metal (e.g., hafnium) by forming insoluble nitrides of the metals in a molten metal solvent (e.g., copper) inert to nitrogen and having a suitable density for the light metal nitride to form a separate phase in the upper portion of the solvent and for the heavy metal nitride to form a separate phase in the lower portion of the solvent. Nitriding is performed by maintaining a nitrogen-containing atmosphere over the bath. The light and heavy metals may be an oxide mixture and carbothermically reduced to metal form in the same bath used for nitriding. The nitrides are then separately removed and decomposed to form the desired separate metals.

Abstract: Novel selenium-75 derivatives of cholesterol have the formula ##STR1## (I) where X is hydrogen or acyl, Y is alkyl and n is 0 or 1. They are useful for visualizing the adrenal glands of mammals.