Dependence of Si-Faceted Dendrite Growth Orientation on Twin Spacing and Undercooling
Dependence of Si-Faceted Dendrite Growth Orientation on Twin Spacing and Undercooling
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DOI：
10.1021/cg101721v
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发表时间：
2011-02
影响因子：
3.8
通讯作者：
Xinbo Yang;K. Fujiwara;K. Maeda;J. Nozawa;H. Koizumi;S. Uda
中科院分区：
文献类型：
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作者：
Xinbo Yang;K. Fujiwara;K. Maeda;J. Nozawa;H. Koizumi;S. Uda
通过原位观察，研究了单面枝晶的生长取向与孪晶间距和过冷度的关系，并对其生长机制进行了讨论和澄清。硅面枝晶的生长取向强烈地依赖于孪晶间距和过冷度。对于给定的过冷度，孪晶间距小于临界孪晶间距的枝晶优先沿⟨110⟩方向生长，而孪晶间距大于临界孪晶间距的枝晶优先沿⟨112⟩方向生长。稳定小面枝晶生长的临界孪晶间距随着过冷度的增加而增大。在低过冷度(∼10K<；ΔT≲15K)的情况下，枝晶主要沿⟨112⟩方向生长。对于高过冷度(∼25K<；ΔT≲100K)，枝晶优先沿⟨110⟩方向生长。⟨110⟩和⟨112⟩生长方向在中间过冷度(∼15K和lt；ΔT≤25K)出现的频率相同。
Si-faceted dendrites growth orientation as a function of twin spacing and undercooling were investigated by in situ observation, and the mechanisms of the growth behaviors were discussed and clarified. The growth orientation of Si-faceted dendrites strongly depends on the twin spacing and undercooling. For a given undercooling, a dendrite with twin spacing narrower than the critical twin spacing preferentially grows in the ⟨110⟩ direction, whereas growth in the ⟨112⟩ direction preferentially occurs for a dendrite with twin spacing wider than the critical twin spacing. The critical twin spacing for stable faceted dendrite growth increases as the undercooling increases. In the case of low undercooling (∼10 K < ΔT ≲ 15 K), dendrites dominantly grow in the ⟨112⟩ direction. For high undercooling (∼25 K< ΔT ≲ 100 K), dendrites preferentially grow in the ⟨110⟩ direction. ⟨110⟩ and ⟨112⟩ growth directions occur with equal frequency for intermediate values of undercooling (∼15 K < ΔT ≤ 25 K).