冰的配置XIX及其同位素效应
Tobias M Gasser1, Alexander V Thoeny1, A Dominic Fortes2
1Institute of Physical Chemistry, University of Innsbruck, 6020, Innsbruck, Austria.
Scientific reports
|May 7, 2024
概括
这项研究量化了冰XIX的配置,揭示了它比冰XV有更大的秩序. 研究人员确定了冰XIX的相极限和热力学稳定性,并在其相图中解释了同位素效应.
科学领域:
- 材料科学 材料科学 材料科学
- 物理化学 物理化学
- 热力学是一种热力学.
背景情况:
- 冰XIX是一种部分排序的多态,与无序冰VI有关,与冰XV相似.
- 研究秩序-混乱-秩序序列 (冰XIX →冰XV →冰VI) 是复杂的,因为重叠的过渡和缓慢的动力学.
研究的目的:
- 为了确定冰XIX,冰XV和冰VI之间的配置差异.
- 确定冰的相位边界和热力学稳定区域XIX.
- 解释冰的第十九阶段图中观察到的同位素转移逆转.
主要方法:
- 对于D2O和H2O冰在环境压力下进行热量测量实验 XIX.
- 使用不同加热速率和采用"单峰集成"和"联合峰集成"方法分析慢动力学.
- 结合了中子粉衍射体积差异和热量计差异数据.
主要成果:
- 冰XIX比冰XV有更大的排序,估计保林的25%±3% (D2O-冰XIX有缺陷的28%).
- 在环境压力下,秩序-混乱过渡温度 (To-d) 为103 K ± 1 K,克拉佩隆斜率为21 K GPa−1.1.
- 在更高的压力下,相位边界斜率会变平,To-d (±1.8 GPa) =116 K ±3 K,这解释了同位素转移的逆转.
结论:
- 该研究成功量化了冰XIX的配置及其与冰XV和冰VI的关系.
- 冰XIX的热力学稳定区域在相位图中定义.
- 这些发现提供了对高压冰相中的相变和同位素效应的全面了解.
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