Accession Number : AD0831534

Title :   RESEARCH FOR HYDROTHERMAL GROWTH OF SINGLE CRYSTALS.

Descriptive Note : Technical Management rept. no. 2, 16 Jan-15 Apr 68,

Corporate Author : TEM-PRES RESEARCH INC STATE COLLEGE PA

Personal Author(s) : Hill, Vincent G. ; Harker, Robert I.

Report Date : 30 APR 1968

Pagination or Media Count : 33

Abstract : The causes of 'veiling' or bubble trains, networks of fractures, and uneven chromium distribution, which are usually found in hydrothermally grown rubies, have been determined. 'Veiling' is caused by the presence of major defect areas in the seed crystals. These may occur when the seeds are sawed, and can be removed by etching away the damaged areas in a solvent like molten KHSO4. The network of fractures may be associated with the 'veiling', but they are also caused by thermal shock. Uneven chromium distribution may result from local precipitation or re-solution of chromium inside the autoclave. These problems have been solved by modifications in the method of seed preparation, design of vessel liner, and the use of 2 molar K2CO3 solution as the hydrothermal solution. (Author)

Descriptors :   *CRYSTAL GROWTH), (*LASERS, RUBY), (*RUBY, SINGLE CRYSTALS, NUCLEATION, DEFECTS(MATERIALS), BUBBLES, DISLOCATIONS, ETCHING, THERMAL SHOCK, IMPURITIES, CHROMIUM, DISTRIBUTION, CHEMICAL PRECIPITATION, INFRARED SPECTRA, POTASSIUM COMPOUNDS, SULFATES, CRYSTAL DEFECTS.

Subject Categories : Lasers and Masers
      Crystallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE