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arXiv · 2009.07333

Widely Spaced Planes of Magnetic Dimers in the Ba6Y2Rh2Ti2O17-δ Hexagonal Perovskite

Loi T. Nguyen·Daniel B. Straus·Q. Zhang·R. J. Cava
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Abstract

We report the synthesis and initial characterization of Ba6Y2Rh2Ti2O17-δ, a previously unreported material with a hexagonal symmetry structure. Face-sharing RhO6 octahedra form triangular planes of Rh2O9 dimers that are widely separated in the perpendicular direction. The material displays a small effective magnetic moment, due to the Rh ions present, and a negative Curie-Weiss temperature. The charge transport and optical band gaps are very similar, near 0.16 eV. A large upturn in the heat capacity at temperatures below 1 K, suppressed by applied magnetic fields larger than {μ0H = 2 Tesla, is observed. A large T-linear term in the specific heat (γ=166 mJ/mol f.u-K2) is seen, although the material is insulating at low temperatures. These results suggest the possibility of a spin liquid ground state in this material.

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Loi T. Nguyen, Daniel B. Straus, Q. Zhang, R. J. Cava. 2020-12-20. Widely Spaced Planes of Magnetic Dimers in the Ba6Y2Rh2Ti2O17-δ Hexagonal Perovskite. https://doi.org/10.1103/physrevmaterials.5.034419

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