Berlin 2018 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 7: Focus Session: Magnetism in Materials Science: Thermodynamics, Kinetics and Defects I (joint session MM/MA)
MA 7.8: Vortrag
Montag, 12. März 2018, 13:00–13:15, TC 010
Symmetry breaking induce robust monoclinic-distortion and unconventional charge ordering at room temperature in single crystal of Na2.7Ru4O9 — •Arvind Yogi1,2, C. I. Sathish1,2, Hasung Sim1,2, Y. Noda3, and Je-Geun Park1,2 — 1Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 08826, Korea — 2Department of Physics and Astronomy, Seoul National University, Seoul 08826, Korea — 3Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577, Japan
We discovered by combining the results of SC-XRD, electrical resistivity, specific heat, and susceptibility that Na2.7Ru4O9 with the monoclinic new tunnel type lattice (space group P 21/m) evolves an unprecedentedly charge ordering (CO) at room temperature while retaining of metallicity. The temperature dependent SC-XRD results shows super-lattice peaks q1 (0, 1/2, 0) and q2 (0, 1/3, 1/3), that causes the translation symmetry breaking of the lattice which induces robust monoclinic-distortion at room temperature, is the evidence for the formation of an unconventional charge ordering (CO). Na2.7Ru4O9 show a first-order phase transition in the electrical resistivity with two consecutive transitions at Tc (1) = 365 K and Tc (2) = 345 K for Na2.7Ru4O9 which supports well by magnetization and heat-capacity results. The electron-phonon mediated scattering mechanism is involved in the resistivity. We argue that the origin of unprecedented CO is due to the localized 4d electrons.