在合体悬浮液中异质晶核形成的开始
A Cacciuto1, S Auer, D Frenkel
1FOM Institute for Atomic and Molecular Physics, Kruislaan 407, 1098 SJ Amsterdam, The Netherlands. cacciuto@amolf.nl
Nature
|March 26, 2004
概括
外来种子颗粒加速晶体核形成,但只有当它们超过最小大小时. 较小的种子起到催化剂的作用,而较大的种子会被覆盖,从而影响晶体尺寸的分布.
科学领域:
- 物理化学 物理化学
- 材料科学 材料科学 材料科学
- 体科学 体科学 体科学
背景情况:
- 用相同结构的粒子播种超和溶液可以增强晶体核形成.
- 外来种子物质促进核形成的机制在微观水平上仍然不太清楚.
研究的目的:
- 研究由外来球形粒子播种的合晶体结晶的微观机制.
- 为了确定种子颗粒大小对核化过程和自由能量屏障的影响.
主要方法:
- 硬体颗粒悬浮物的蒙特卡洛模拟.
- 计算结晶核形成的自由能量屏障.
- 分析种子颗粒大小对促进结晶的影响.
主要成果:
- 需要最小的种子颗粒大小才能有效地促进结晶.
- 刚刚超过最小尺寸的种子起到催化剂的作用,释放新形成的晶体.
- 较大的种子被结晶体覆盖,改变了核化行为.
结论:
- 外来种子颗粒可以有效地促进合结晶,但大小是一个关键因素.
- 观察到的尺寸依赖性行为为控制晶体尺寸分布提供了一条途径.
- 这些发现提供了对外种植的微观理解,并表明了实验验证性.
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