Growth of Ruby Crystals by the Heat Exchanger Method, Phase I - NSF Small Business Innovation Research

摘要

Conditions for the growth of large, uniformly doped laser crystals by the Heat Exchanger Method are explored. This development enhances laser applications which heretofore have been limited by the availability of suitable quality and/or size of materials. This study involved determination of the melt point, selection of crucible material and establishment of furnace operating parameters. The melt point of ruby was found to be 2040 plus or minus 10 C. Molybdenum crucibles can be used to contain ruby in vacuum as well as under argon atmospheres at desired superheat temperatures over extended periods required for crystal growth. Volatilization of chromium oxides at superheat temperatures proved to be the major problem. Thermodynamic analysis was conducted and vapor pressures of volatile species calculated. Experimentally, volatilization of chromium oxides was suppressed by using welded covers on crucibles and operating under an argon pressure in the furnace.