Sample-dependent and sample-independent thermal transport properties of α – RuCl 3

Journal Article · 13 November 2023 · Physical Review Materials

DOI: https://doi.org/10.1103/physrevmaterials.7.114403 · OSTI ID:2217727

Zhang, Heda ^[1]; May, Andrew F.  ^[1]; Miao, Hu  ^[1]; Sales, Brian C.  ^[1]; Mandrus, David G. ^[1]; Nagler, Stephen E.  ^[1]; McGuire, Michael A.  ^[1]; Yan, Jiaqiang  ^[1]

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1. Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)

In this study, we investigated the thermal transport properties of two α–RuCl₃ crystals with different degrees of stacking disorder to understand the origin of the previously reported oscillatory feature in the field dependence of thermal conductivity. Crystal I shows only one magnetic order around 13 K, which is near the highest T_N for α–RuCl₃ with stacking faults. Crystal II has less stacking disorder, with a dominant heat capacity at 7.6 K along with weak anomalies at 10 and 13 K. In the temperature and field dependence of thermal conductivity, no obvious anomaly was observed to be associated with the magnetic order around 13 K for either crystal or around 10 K for crystal II. Crystal II showed clear oscillations in the field dependence of thermal conductivity, while crystal I did not. For crystal I, an L-shaped region in the temperature-field space was observed where thermal Hall conductivity κ_xy/T is within ±20% of the half quantized thermal Hall conductivity κ_HQ/T, while for crystal II, κ_xy/T reaches κ_HQ/T only in the high field and high temperature regime with no indication of a plateau at κ_HQ/T. Our thermal conductivity data suggest the oscillatory features are inherent to the zigzag ordered phase with T_N near 7 K. Our planar thermal Hall effect measurements suggest the sensitivity of this phenomena to stacking disorder. Overall, our results highlight the importance of understanding and controlling crystallographic disorder for obtaining and interpreting intrinsic thermal transport properties in α–RuCl₃.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States); National Quantum Information Science (QIS) Research Centers (United States). The Quantum Science Center (QSC)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES). Materials Sciences & Engineering Division (MSE)
• Grant/Contract Number: AC05-00OR22725
• OSTI ID: 2217727
• Journal Information: Physical Review Materials, Vol. 7, Issue 11; ISSN 2475-9953
• Publisher: American Physical Society (APS)Copyright Statement
• Country of Publication: United States
• Language: English