Dataset for 'Strain-Relief by Single Dislocation Loops in Calcite Crystals Grown on Self-Assembled Monolayers'

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 visualise 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 r oughness 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.

目前学界关于外延晶体生长过程中位错介导的应力弛豫的认知，大多源于对无机异质结构的研究。本研究采用布拉格相干衍射成像（Bragg Coherent Diffraction Imaging）技术，对另一类体系展开探究：有机自组装单分子层表面方解石（CaCO₃）晶体的外延生长——该体系被广泛用作生物矿化过程的模型体系。实验中，我们通过成像同时可视化方解石晶体的形貌与内部应变场。数据显示，每颗晶体均存在一个位错环，且该位错环在所有晶体中均位于同一位置。此类位错环与传统外延薄膜中产生的失配位错在几何构型上完全不同，研究推测其形成源于界面缺陷与基底纳米级粗糙度所引发的应力场。本研究为理解自组装单分子层调控无机晶体生长的机制提供了独特视角，并揭示了其与无机基底调控晶体生长过程的显著差异。