Strain-relief by single dislocation loops in calcite crystals grown on self-assembled monolayers.
Strain-relief by single dislocation loops in calcite crystals grown on self-assembled monolayers.
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DOI：
10.1038/ncomms11878
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发表时间：
2016-06-15
影响因子：
16.6
通讯作者：
Meldrum FC
中科院分区：
文献类型：
--
作者：
Ihli J;Clark JN;Côté AS;Kim YY;Schenk AS;Kulak AN;Comyn TP;Chammas O;Harder RJ;Duffy DM;Robinson IK;Meldrum FC
我们对外延晶体生长过程中位错介导的应力松弛的认识大多来自于对无机异质结构的研究。在这里，我们使用布拉格相干衍射成像研究对比系统，方解石（碳酸钙）晶体的有机自组装单分子膜上的外延生长，这些被广泛用作生物矿化过程的模型。方解石晶体成像，同时可视化的晶体形态和内部应变场。我们的数据表明，每个晶体具有一个单一的位错环，占据了每个晶体中的共同位置。环表现出完全不同的几何形状，在传统的外延薄膜中产生的失配位错，并建议形成响应于应力场，所产生的界面缺陷和纳米级粗糙度的衬底。这项工作提供了独特的见解如何自组装单分子膜控制无机晶体的生长，并证明了重要的差异，与无机基板相比。 外延晶体生长引起了人们极大的兴趣。在这里，作者使用布拉格相干衍射成像来证明方解石晶体沉淀在自组装单层上，表现出与传统外延薄膜中产生的具有不同几何形状的单个位错环。
Most of our knowledge of dislocation-mediated stress relaxation during epitaxial crystal growth comes from the study of inorganic heterostructures. Here we use Bragg coherent diffraction imaging to investigate a contrasting system, the epitaxial growth of calcite (CaCO3) crystals on organic self-assembled monolayers, where these are widely used as a model for biomineralization processes. The calcite crystals are imaged to simultaneously visualize the crystal morphology and internal strain fields. Our data reveal that each crystal possesses a single dislocation loop that occupies a common position in every crystal. The loops exhibit entirely different geometries to misfit dislocations generated in conventional epitaxial thin films and are suggested to form in response to the stress field, arising from interfacial defects and the nanoscale roughness of the substrate. This work provides unique insight into how self-assembled monolayers control the growth of inorganic crystals and demonstrates important differences as compared with inorganic substrates. Epitaxial crystal growth attracts significant interest. Here, the authors use Bragg Coherent Diffraction Imaging to demonstrate calcite crystal precipitation on self-assembled monolayers exhibiting single dislocation loops with different geometries to those generated in conventional epitaxial thin films.