Institute of Physical Chemistry, University of Innsbruck, Innrain 52c, A-6020 Innsbruck, Austria.
Consiglio Nazionale delle Ricerche, Istituto di Fisica Applicata 'Nello Carrara', via Madonna del Piano 10, I-50019 Sesto Fiorentino, Italy.
J Phys Chem Lett. 2023 Jun 1;14(21):5055-5060. doi: 10.1021/acs.jpclett.3c00408. Epub 2023 May 25.
The preparation of pure cubic ice without hexagonal stacking faults has been realized only recently by del Rosso et al. ( 2020, 19, 663-668) and Komatsu et al. ( 2020, 11, 464). With our present calorimetric study on the transition from pure cubic ice to hexagonal ice we are able to clarify the value of the enthalpy change Δ to be -37.7 ± 2.3 J mol. The transition temperature is identified as 226 K, much higher than in previous work on ice I. This is due to a catalytic effect of hexagonal faults on the transition, but even more importantly due to a relaxation exotherm that was not properly identified in the past.
最近，del Rosso 等人（2020 年，19 卷，663-668）和 Komatsu 等人（2020 年，11 卷，464）才实现了纯净立方冰而没有六方堆积缺陷的制备。通过我们目前对从纯立方冰到六方冰的转变的量热研究，我们能够澄清焓变 Δ 的值为-37.7±2.3 J mol。转变温度被确定为 226 K，远高于之前关于冰 I 的研究。这是由于六方缺陷对转变的催化作用，但更重要的是由于过去没有正确识别的弛豫放热。
