| 摘要 |
PURPOSE:To suppress contamination of platinum particles into a single crystal, by providing a double wall of a platinum crucible for forming single crystals by the Bridgman process, intermittently introducing cooling gas into the gap between the inner and the outer walls and keeping the inner wall temperature below the melting temperature of a raw material. CONSTITUTION:A platinum (alloy) crucible 1 is installed movably in the vertical direction in a heating device 2 and the platinum crucible 1 is constructed of double wall consisting of an inner wall 4 and outer wall 6. An introductory pipe 7 and discharge pipe 8 for a cooling gas are provided in a hermetically sealed gap 9 formed between the inner and outer walls 4 and 6. A raw material is fed into the crucible 1, heated with the heating device 1 while vertically moving the crucible 1 and melted. A cooling gaseous substance is intermittently introduced into the hermetically sealed gap 9 and discharged therefrom to keep the temperature of the inner wall 4 of the crucible 1 below the melting temperature of the raw material at the same time. The molten raw material is then annealed to grow a crystal and afford the aimed single crystal.
|
