Schnelle, W., Prasad, B.E., Felser, C., Jansen, M., Komleva, E.V., Streltsov, S.V., Mazin, I.I., Khalyavin, D., Manuel, P., Pal, S., Muthu, D.V.S., Sood, A.K., Klyushina, E.S., Lake, B., Orain, J.C., and Luetkens, H.
The silver ruthenium oxide AgRuO3 consists of honeycomb Ru25+O62- layers and can be considered an analogue of SrRu2O6 with a different intercalation. We present measurements of magnetic susceptibility and specific heat on AgRuO3 single crystals, which reveal a sharp antiferromagnetic transition at 342(3) K. The electrical transport in single crystals of AgRuO3 is determined by a combination of activated conduction over an intrinsic semiconducting gap of ≈100 meV and carriers trapped and thermally released from defects. From powder neutron diffraction data a Néel-type antiferromagnetic structure with the Ru moments along the c axis is derived. Raman spectroscopy on AgRuO3 single crystals and muon spin rotation spectroscopy on powder samples indicate a further weak phase transition or a crossover in the temperature range 125-200 K. The transition does not show up in the magnetic susceptibility, and its origin is argued to be related to defects but cannot be fully clarified. The experimental findings are complemented by density-functional-theory-based electronic structure calculations. It is found that the magnetism in AgRuO3 is similar to that in SrRu2O6, however, with stronger intralayer and weaker interlayer magnetic exchange interactions. © 2021 authors. Published by the American Physical Society. We thank S. Scharsach and M. Schmidt for the DSC measurements and M. Baenitz and C. Shekhar for some measurements (not shown) in the early stage of this study. A.K.S. acknowledges the Department of Science and Technology (DST), India. S.P. received support from a DST Inspire Fellowship. I.I.M. acknowledges support from the U.S. Department of Energy through Grant No. DE-SC0021089. E.V.K. and S.V.S. thank the Russian Foundation for Basic Research (Grants No. 20-32-70019 and No. 20-32-90073) and the Russian Ministry of Science and Higher Education via program “Quantum” (Grant No. AAAA-A18-118020190095-4) and Contract No. 02.A03.21.0006. B.L. acknowledges support from the Deutsche Forschungsgemeinschaft (DFG) through Project No. B06 of the SFB 1143 (ID:247310070). This work is partially based on experiments performed at the Swiss Muon Source , Paul Scherrer Institute, Villigen, Switzerland.