Improvements in or relating to the control of the internal junction structure of a crystal

摘要

PICT:0788375/III/1 In a method of producing predetermined junctures in a crystal grown from a melt in a vessel, coincident plural seedgrowths of different stratification are initiated in the melt in a plurality of extensions to the vessel, and the respective seed-growths therefrom are allowed to penetrate into the main body of the vessel at equal growth rates whereby the crystal formed in the vessel is composed of component portions of the plurality of coincident growths, thereby forming junctures at their respective contacting faces within the crystal. A tubular vessel 1 having two radially conically formed extensions 2 and 3 is filled with material, such as bismuth and antimony, which is melted by heating coils 7, 8, 12, 14 and 16, and the temperature in extensions 2 and 3 is lowered by adjusting a rheostat 11 to initiate seed growth at terminals 5 and 6, from which crystals of different orientation grow until they unite at 4. A temperature gradient is maintained in the main body of the vessel 1 by adjusting rheostats 13, 15 and 17 to cause a crystal to grow therein having a junction face 20 between the two parts of the crystal 18 and 19 having different laminations or strata. In another embodiment, a vessel is used having four extensions similar to 2 and 3 above, and a crystal is grown having four segments of different orientation. In a modification, the vessel 1 has two conical extensions, with open ends, at the lower end and crystal seeds having differing orientation are placed against the open ends, the two parts of the crystal being grown from the seeds by adjustment of temperature as above.