冰的多态转变和液体-液体临界点的传播
Osamu Mishima1, Yoshiharu Suzuki
1Advanced Materials Laboratory, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044 Japan. mishima.osamu@nims.go.jp
Nature
|October 11, 2002
概括
该研究表明,高密度和低密度无形冰之间的过渡是一个不连续的相位过渡. 这一发现表明水是水.
科学领域:
- 物理化学 物理化学
- 材料科学 材料科学 材料科学
- 热力学是一种热力学.
背景情况:
- 水表现出复杂的转移稳定相位行为,包括高密度和低密度无形冰和超冷液体之间的过渡.
- 这些转变发生在晶体冰在热力学稳定的条件下,这使得直接的实验研究具有挑战性.
- 液态水过渡的性质 (连续或不连续) 和第二个临界点的存在仍在争论中.
研究的目的:
- 研究高密度无形冰 (HDA) 与低密度无形冰 (LDA) 之间的相位过渡的热力学性质.
- 基于无形冰研究,提供对超冷液态水相位行为的见解.
- 为了澄清无形冰中的多态过渡是连续的还是不连续的.
主要方法:
- 拉曼光谱法用于分析HDA到LDA转换期间的结构变化.
- 视觉检查被用来观察相变的物理特征.
- 实验的重点是描述相位边界的传播和演变.
主要成果:
- 从HDA转变为LDA涉及到一个独特的相位边界的传播,其中包含了两种冰形式的混合物.
- 观察到这种相位边界随着变化的进展和温度的增加而变得越来越窄.
- 观察到的边界动态强烈表明了不连续的相位过渡.
结论:
- 在HDA和LDA之间的多态过渡是不连续的,以传播相极限为特征.
- 无形冰和超冷液体之间的结构相似性表明,液态水也经历了不连续的过渡.
- 这些发现支持了水的液体-液体临界点理论.
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