| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a single crystal production apparatus capable of impressing a radial cusped magnetic field of coaxial symmetry to the neighborhood of the center of a fusion of crystal material inside a crucible in a crystal pulling section to improve crystal properties by the use of a magnetic field generator for impressing a magnetic field into the fusion of crystal material. SOLUTION: This single crystal production apparatus comprises a single-crystal pulling section and a magnetic field generator section for providing a magnetic field for a fusion section for a single crystal material in such a configuration that on both sides of the crystal pulling section a pair of main coils and a pair of subsidiary coils which have a smaller diameter than that of the main coils and whose exciting direction is coaxial and opposite to the main coils. In this configuration of the single crystal production apparatus of magnetic field impression type shown in the figure, a crucible 2 filled with a single crystal fusion material 1 is heated by a heater 3 so as to be maintained constantly in fused condition. A seed crystal 4 is pulled up at a constant speed. The superconductive main coils 21a and subsidiary coils 21b generates a magnetic field in vertical direction as shown by the direction of field impression 11 in the crucible 2. As a result, the heat convection 8 induced by the heater 3 is substantially controlled by magnetic resistance caused by the magnetic field in the vertical direction.</p> |
