GROWTH DEVICE, CRYSTAL GROWTH AND CHARACTERIZATION OF ALEXANDRITE

Alexandrite is beryllium aluminate Al2O3•BeO doped with minor levels of chromophores, Cr2O3 being the major one. The engineering application of single crystals of synthetic alexandrite is currently limited to active elements of tunable IR-lasers for remote sensing and medicine. In the design of the mechanical components of any crystal-growth systems, especially high-temperature systems, there are two basic requirements: long-term stability of the dimensions of the heating equipment; and uniform rotary and translational motion of the crystal over a wide speed range. Accordingly, it is assumed for the heating system that the heater and internal screens are made of tungsten and the heater is cylindrical. In the present work, authors describe a new high-temperature furnace for a crystal-growth system, with new designs of the heater, screens, copper leads, and the lid. To eliminate the sealed input, which is the primary source of non-uniform crystal motion, the kinematic system, including the motor, is placed in a volume connected to the furnace