Alkemade Rinske M, de Jager Marjolein, van der Meer Berend, Smallenburg Frank, Filion Laura
Soft Condensed Matter, Debye Institute of Nanomaterials Science, Utrecht University, Utrecht, The Netherlands.
Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, South Park Road, Oxford OX1 3QZ, United Kingdom.
J Chem Phys. 2021 Apr 28;154(16):164905. doi: 10.1063/5.0047034.
Charged colloidal particles-on both the nano and micron scales-have been instrumental in enhancing our understanding of both atomic and colloidal crystals. These systems can be straightforwardly realized in the lab and tuned to self-assemble into body-centered-cubic (BCC) and face-centered-cubic (FCC) crystals. While these crystals will always exhibit a finite number of point defects, including vacancies and interstitials-which can dramatically impact their material properties-their existence is usually ignored in scientific studies. Here, we use computer simulations and free-energy calculations to characterize vacancies and interstitials in FCC and BCC crystals of point-Yukawa particles. We show that, in the BCC phase, defects are surprisingly more common than in the FCC phase, and the interstitials manifest as so-called crowdions: an exotic one-dimensional defect proposed to exist in atomic BCC crystals. Our results open the door to directly observe these elusive defects in the lab.
纳米和微米尺度的带电胶体粒子有助于增进我们对原子晶体和胶体晶体的理解。这些系统在实验室中可以直接实现，并可调整以自组装成体心立方（BCC）和面心立方（FCC）晶体。虽然这些晶体总会表现出有限数量的点缺陷，包括空位和间隙原子——这会极大地影响它们的材料性能——但在科学研究中它们的存在通常被忽略。在这里，我们使用计算机模拟和自由能计算来表征点- Yukawa粒子的FCC和BCC晶体中的空位和间隙原子。我们表明，在BCC相中，缺陷比在FCC相中出奇地更常见，并且间隙原子表现为所谓的挤列子：一种被认为存在于原子BCC晶体中的奇特一维缺陷。我们的结果为在实验室中直接观察这些难以捉摸的缺陷打开了大门。
