Abstract The top surface of a crystal–melt interface was observed directly during directional solidification of polycrystalline GaSb at a constant cooling rate, and the effect of {111}Σ3 twin boundary formation on the rate of grain growth parallel to the 〈111〉 direction was investigated. A {111}Σ3 twin boundary was generated by the decomposition of another {111}Σ3 twin boundary with formation of a Σ9 grain boundary. The growth of the crystal–melt interface in the direction parallel to the B direction was stalled during the nucleation and propagation of the new {111}Σ3 twin boundary. The growth rate of the crystal–melt interface after twin formation was approximately half of that before. This is considered to be due to {111} polarity reversal by twinning. The dangling bond density on the {111}A plane of GaSb is almost ten times of that on the {111}B plane, and the dangling bond density is related to the attachment energy of atoms of the plane; therefore, the growth rate in the A direction would be significantly lower than that in the B direction. These results indicate different growth rates in opposite 〈111〉 directions and a significant effect of the polarity on the competition of grain growth during the directional solidification of polycrystalline GaSb.

中文翻译：

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双晶界形成对GaSb{111}面生长速率的影响

摘要 在多晶 GaSb 以恒定冷却速率定向凝固过程中直接观察到晶体-熔体界面的顶面，{111}Σ3 孪晶界的形成对平行于〈111〉方向的晶粒生长速率的影响为调查。{111}∑3孪晶界是由另一个{111}∑3孪晶界分解产生的，形成∑9晶界。在新的 {111}Σ3 孪晶界的成核和传播过程中，晶体-熔体界面在平行于 B 方向的方向上的生长停滞。孪晶形成后晶体-熔体界面的生长速率约为之前的一半。这被认为是由于孪晶导致的{111}极性反转。GaSb在{111}A面的悬空键密度几乎是{111}B面的10倍，且悬空键密度与该面原子的附着能有关；因此，A 方向的增长率将明显低于 B 方向的增长率。这些结果表明在相反的<111> 方向上的不同生长速率和极性对多晶 GaSb 定向凝固过程中晶粒生长竞争的显着影响。