Accession Number : AD0652375

Title :   HYDROTHERMAL GROWTH OF CRYSTALS OF LAALO3.

Descriptive Note : Final rept., 14 Aug 64-14 Aug 66.

Corporate Author : AIRTRON INC MORRIS PLAINS N J

Report Date : 14 AUG 1966

Pagination or Media Count : 58

Abstract : Two new molten salt solvent systems were found from which LaAlO3 could be crystallized, PbF2-B2O3 and Bi2O3 - B2O3. The conditions and compositions for using these solvents were developed so that crystals one half to one inch on edge were grown. In the PbF2-B2O3 system the most successful growth was accomplished by operating in the 1500-1200C temperature range. In the case of the Bi2O3-B2O3 system there is an acceleration of the grain growth of the platinum, which leads to premature failure of the crucibles. The crystallization paths for LaAlO3 growth were studied for melts containing stoichiometric quantities of La2O3 and Al2O3 and also Al2O3 rich melts. The initial work in small reactors in the hydrothermal system appeared most encouraging. Almost immediately a suitable solvent, K2CO3, was found and after experimentation with the system variables, growth on seeds was obtained below a crystallization temperature of 425C. In these runs flux grown LaAlO3 crystals were used for seeds and nutrient. In large autoclaves only limited success was achieved with crystal growth in both two and three zone systems.

Descriptors :   (*LASERS, MATERIALS), (*LANTHANUM COMPOUNDS, *CRYSTAL GROWTH), (*ALUMINATES, CRYSTAL GROWTH), SOLVENTS, LEAD COMPOUNDS, FLUORIDES, BORON COMPOUNDS, BISMUTH COMPOUNDS, OXIDES, SINGLE CRYSTALS, DOPING, CHROMIUM, CRYSTALLIZATION, PHASE STUDIES, POTASSIUM COMPOUNDS, COBALT COMPOUNDS, SCALE

Subject Categories : Lasers and Masers
      Crystallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE