Accession Number : AD0814756

Title :   DEVELOPMENT OF HYDROTHERMAL METHOD FOR GROWING SINGLE CRYSTALS OF HIGH PURITY BERYLLIUM OXIDE AND THE STUDY OF THE FEASIBILITY OF HYDROTHERMAL GROWTH OF SELECTED CRYSTALS.

Descriptive Note : Progress rept. no. 2, 16 Jan-15 Apr 67,

Corporate Author : TEM-PRES RESEARCH INC STATE COLLEGE PA

Personal Author(s) : Hill, V. G. ; Harker, R. I.

Report Date : 01 MAY 1967

Pagination or Media Count : 48

Abstract : Beryllium oxide crystals weighing up to 1.3 grams have been grown hydrothermally with the nutrient temperature at 530 + or - 5 C and the growth temperature at 500 + or - 5 C. Four normal potassium hydroxide solution, which is also 0.06 normal with respect to LiOH, was used as hydrothermal solution. Growth occurred in the vapor phase above the hydroxide solution. The quality of the seeds used has a major effect on the quality of the crystals grown. X ray diffraction topographs confirmed that the crystals grown on 00.1 (crystallographic direction) seeds are more subject to mosaicity than those grown on either the 11.0 or 10.1 (crystallographic direction) seeds, but the 00.1 (crystallographic direction) growth is more tolerant to the presence of higher levels of LiOH. The topographs confirm that the best crystals were obtained when high quality 11.0 or 10.1 (crystallographic direction) seeds were overgrown in a solution which is also 0.06 normal with respect to LiOH. Infrared studies of selected crystals show that the bonded water can be extracted to below 70 ppm.

Descriptors :   *BERYLLIUM OXIDES), (*CRYSTAL GROWTH, (*NIOBATES, CRYSTAL GROWTH), SINGLE CRYSTALS, TEMPERATURE, SOLUTIONS(MIXTURES), POTASSIUM COMPOUNDS, LITHIUM COMPOUNDS, HYDROXIDES, SOLUBILITY, NUCLEATION, VAPORS, IMPURITIES.

Subject Categories : Crystallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE