| 摘要 |
PURPOSE:To provide stable thermal characteristics irrespective of number of times of use by incorporating Al2O3 added with a specific amount of Cr in a core tube used for an electric furnace using a heat generator containing LaCrO3 as a main ingredient. CONSTITUTION:A core tube 1 in which Al2O3 of 99.9% of purity is added with 1.5-3wt.% of Cr is installed at a center, and a heat generator 2 containing LaCrO3 as a main ingredient is so disposed as to be concentrically extended from the tube 1. Oxide single crystal is grown in the tube. A material change of the tube 1 due to reaction with Cr evaporated from the LaCrO3 of the generator 2 is reduced, and a change amount of thermal characteristics of the tube 1 can be suppressed. Thus, even when the crystal which is continuously operated for a long time is used or repeatedly used, stable thermal characteristics are obtained. |
