Beyond Simple Crystal Systems: Identifying Twinning in Body-Centered Tetragonal Nanoparticles
Beyond Simple Crystal Systems: Identifying Twinning in Body-Centered Tetragonal Nanoparticles
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DOI：
10.1021/acs.cgd.1c01188
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发表时间：
2021-12-16
影响因子：
3.8
通讯作者：
Ringe, Emilie
中科院分区：
文献类型：
--
作者：
Boukouvala, Christina;Hopper, Elizabeth R.;Ringe, Emilie
虽然许多元素以体心立方、六方密堆积或面心立方结构结晶，但In和β-Sn采用体心四元晶胞。这两种元素作为纳米颗粒（NPs）越来越受欢迎，报道了不同的单晶和孪生NPs。在这里，我们提出了一个系统的研究所需的晶体形状和方法，以确定在和β-Sn的孪晶的存在下，与适用于其他简单的体心四面体晶体，如化合物和超晶格。良好的多面晶体可以根据形状显示孪晶，但这通常被拐角圆化所掩盖，在这种情况下需要衍射或晶格成像。我们描述了一组有限的低指数取向，提供电子衍射图案或原子分辨率图像能够区分单晶和孪晶，并发现双胞胎在β-Sn更容易识别由于额外的原子在晶胞。
While many elements crystallize in body-centered cubic, hexagonal close packed, or face-centered cubic structures, In and beta-Sn adopt a body-centered tetragonal unit cell. Both elements are gaining popularity as nanoparticles (NPs), with different single crystal and twinned NPs reported. Here, we present a systematic study of the crystal shapes and approaches required to identify the presence of twinning in In and beta-Sn, with applicability to other simple body-centered tetragonal crystals such as compounds and superlattices. Well-faceted crystals could reveal twinning based on shape, but often this is obscured by corner rounding, in which case diffraction or lattice imaging is required. We describe the limited set of low-index orientations that provide either electron diffraction patterns or atomic resolution images capable of distinguishing between single and twinned crystals and find that twins in beta-Sn are easier to identify owing to the additional atoms in the unit cell.