Investigation of Electron Beam Processing of Aluminum Oxide and Related Materials

摘要

The report is concerned with the application of float-zone crystal growth techniques to refractory non-metallic materials currently of interest to the laser technology. Electron beam and hollow cathode discharge techniques were used to produce the molten zones. The electron beam technique yielded sapphire crystals having diameters up to 5/16 in. Dislocation densities of 100/sq cm were observed. Ruby crystals having similar diameters were also grown, but reveal a pronounced chromium coring because of the large chromium losses which occur in the electron beam environment. The hollow cathode technique yielded sapphire, ruby and yttrium aluminum garnet crystals. Both pure and doped garnet crystals were grown. Multiply doped garnets containing erbium and holmium were produced which do not contain the flawed core exhibited by Czochralski pulled crystals. Only a limited amount of work was done related to ruby growth because of feed rod preparation problems. (Author)