Glassy Anomalies in the Low-Temperature Thermal Properties of a Minimally Disordered Crystalline Solid.
PHYSICAL REVIEW LETTERS 2017;
119:215506. [PMID:
29219416 DOI:
10.1103/physrevlett.119.215506]
[Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Indexed: 06/07/2023]
Abstract
The low-temperature thermal and transport properties of an unusual kind of crystal exhibiting minimal molecular positional and tilting disorder have been measured. The material, namely, low-dimensional, highly anisotropic pentachloronitrobenzene has a layered structure of rhombohedral parallel planes in which the molecules execute large-amplitude in-plane as well as concurrent out-of-plane librational motions. Our study reveals that low-temperature glassy anomalies can be found in a system with minimal disorder due to the freezing of (mostly in-plane) reorientational jumps of molecules between equivalent crystallographic positions with partial site occupation. Our findings will pave the way to a deeper understanding of the origin of the above-mentioned universal glassy properties at low temperature.
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