自相似的半晶体通过接口驱动的核和组装形成
Guomin Zhu1,2, Maria L Sushko1, John S Loring1
1Physical Sciences Division, Pacific Northwest National Laboratory, Richland, WA, USA.
Nature
|February 18, 2021
概括
粒子附着驱动着体结晶,形成复杂的纳米材料. 新的研究揭示了氧化铁中晶形成的接口驱动路径,挑战了以前的模型.
科学领域:
- 体科学
- 材料科学
- 地质化学
背景情况:
- 通过粒子附着 (CPA) 的结晶形成层次的纳米材料和复杂的矿物质质.
- 定向附着是一种CPA形式,产生模仿单晶的中晶体,但保留粒子的身份.
- 传统的CPA观点涉及布朗运动和粒子间潜力,但中晶体的规律性和连接体的作用仍然不清楚.
研究的目的:
- 研究铁氧化物中中晶体形成的机制,这是一个常见的体系统.
- 澄清CPA中的前体阶段和表面结合体的作用.
- 阐明随机附着事件导致有序中晶体结构的过程.
主要方法:
- 在位传输电子显微镜 (TEM) 在80°C.
- "结并观察"的TEM技术.
- 在酸盐 (Ox) 的存在下研究了血 (Hm) 中晶体的形成.
主要成果:
- 很少观察到孤立的血颗粒.
- 氧化物覆盖表面的表面梯度诱导了血颗粒的重复核化.
- 通过接口驱动的路径,核粒子附着在表面,形成中晶体.
结论:
- 半晶体形成是由界面梯度驱动的,而不是仅仅是随机的布朗运动.
- 这种接口驱动的途径为有序的中晶形成提供了新的理解.
- 这些发现表明,在涉及氧化铁和类似的体工艺的自然和合成系统中具有广泛的应用性.
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