| 摘要 |
<PICT:0915732/III/1> <PICT:0915732/III/2> <PICT:0915732/III/3> Zone melting apparatus comprises means for moving an elongated body of material slowly past a plurality of heat sources whereby portions of the material are melted by each source in turn and allowed to solidify in passing between adjacent heat sources, and includes means to permit the portions of the body of material to be melted but to prevent a seed crystal at one end of the body from being melted. In one embodiment a boat 3 (Fig. 1) containing material 7d, e.g. germanium, is slowly pulled by a rod 8 through a tube 1 around which are inductive heating coils 6a, 6b and 6c which produce molten zones 7a, 7b and 7c which pass along the material in boat 3. The boat 3 has an inductive coupling shell 2 (see also Fig. 2), e.g. of graphite, which enables the coils to heat the material and so form the molten zones. One end of the boat contains a seed crystal 7g in contact with the material, and the shell 2 stops short of this end of the boat so that the seed crystal is not melted. In another embodiment (Fig. 3) a tube 8 (e.g. of quartz) containing a boat 9 in which is placed material 1A, is moved relatively to sources of radiant heat 4A, 4B and 4C, so that molten zones 1Da, 1Db and 1Dc are formed and pass along the material. Tube 8 has a shield 5, e.g. of aluminium foil, which prevents a seed crystal 1C from being melted. |
