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sirljz(金币+2, 翻译EPI+1):够认真，谢谢交流，欢迎常来 2010-04-05 13:10
lliang921(金币+20): 2010-04-16 08:50
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The molten zone was very stable for the entire duration of the growth procedure. The power needed to melt the rods accounted for about 55％ of the total output power of the lamps. However, there was a problem that a large number of bubble inclusions were observed in a crystal grown at 10 mm/h with the rotation rate of 30 rpm as shown in Fig. 2(a). In other systems, similar situations were also mentioned. To suppress the bubble inclusion, Seok Gyu Yoon increased the melt temperature, M. HiguchiS et al. used a higher rotation rate and M. Koohpayeh et al. [20] turned rotation rate down to 0 rpm.. In our later work, lower rotation rates of 10 and 5 were applied and the as-grown crystals were denoted as simple 1 and simple 2, respectively. The crystal wafers from simple 1 and simple 2 cut perpendicular to the growth direction and fine polished ? were detected with polarizing microscope. There are few bubble inclusions in the sample 1 as shown in Fig. 2(b). And Fig. 2(c) shows that the sample 2 is free of bubble inclusion. In all cases, no low-angle grain boundary is observed. In conclusion, the as-grown zo crystals are free of bubble inclusion and low-angle grain boundary ; a lower rotation rate is effective to suppress the formation of bubble inclusion in growth of zo crystal. |
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