Li2B12H12 体系中的一级相变。

First-order phase transition in the Li2B12H12 system.

机构信息

Department of Imaging and Applied Physics, Fuels and Energy Technology Institute, Curtin University, GPO Box U1987, Perth 6845, WA, Australia.

出版信息

Phys Chem Chem Phys. 2013 Oct 14;15(38):15825-8. doi: 10.1039/c3cp53090f. Epub 2013 Aug 30.

DOI:10.1039/c3cp53090f

PMID:23995580

Abstract

The thermal decomposition of anhydrous Pa3[combining macron] Li2B12H12 was studied in situ by high resolution synchrotron X-ray diffraction. A first-order phase transition can be observed at 355 °C where the unit cell volume expands by ca. 8.7%. The expanded β-Li2B12H12 polymorph simultaneously decomposes to a hydrogen poor γ-Li2B12H12-x phase. Expansion of the unit cell across the discontinuity is consistent with reorientational motion of B12H12(2-) anions, and the presence of a frustrated Li(+) lattice indicating Li ion conduction.

摘要

采用高分辨率同步辐射 X 射线衍射对无水 Pa3[combining macron]Li2B12H12 的热分解进行了原位研究。在 355°C 可观察到一级相变，此时单元体积膨胀约 8.7%。扩展的β-Li2B12H12 多晶型物同时分解为氢贫 γ-Li2B12H12-x 相。不连续处的单元晶格扩展与 B12H12(2-)阴离子的重定向运动以及受阻 Li(+)晶格的存在一致，表明存在锂离子传导。