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arXiv · 1712.00035

Glassy anomalies in the low-temperature thermal properties of a minimally disordered crystalline solid

J. F. Gebbia·M. A. Ramos·D. Szewczyk·A. Jezowski·A. I. Krivchikov·Y. V. Horbatenko·T. Guidi·F. J. Bermejo·J. Ll. Tamarit
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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 (PCNB) 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 above-mentioned universal glassy properties at low temperature.

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J. F. Gebbia, M. A. Ramos, D. Szewczyk, A. Jezowski, A. I. Krivchikov, Y. V. Horbatenko, T. Guidi, F. J. Bermejo, J. Ll. Tamarit. 2017-11-30. Glassy anomalies in the low-temperature thermal properties of a minimally disordered crystalline solid. https://doi.org/10.1103/physrevlett.119.215506

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