Frustrated spin-1/2 molecular magnetism in the mixed-valence antiferromagnets Ba3MRu2O9 (M = In, Y, Lu)

Abstract

We have performed magnetic susceptibility, heat capacity, muon spin relaxation, and neutron scattering measurements on three members of the family Ba3MRu2O9, where M = In, Y and Lu. These systems consist of mixed-valence Ru dimers on a triangular lattice with antiferromagnetic interdimer exchange. Although previous work has argued that charge order within the dimers or intradimer double exchange plays an important role in determining the magnetic properties, our results suggest that the dimers are better described as molecular units due to significant orbital hybridization, resulting in one spin-1/2 moment distributed equally over the two Ru sites. These molecular building blocks form a frustrated, quasi-two-dimensional triangular lattice. Our zero and longitudinal field muSR results indicate that the molecular moments develop a collective, static magnetic ground state, with oscillations of the zero field muon spin polarization indicative of long-range magnetic order in the Lu sample. The static magnetism is much more disordered in the Y and In samples, but they do not appear to be conventional spin glasses.

References in corpus (18)

• Experimental Realization of Spin-1/2 Triangular-Lattice Heisenberg Antiferromagnet
• Static Critical Behavior of the Spin-Freezing Transition in the Geometrically Frustrated Pyrochlore Antiferromagnet Y2Mo2O7
• Magnetization Process and Collective Excitations in the S=1/2 Triangular-Lattice Heisenberg Antiferromagnet Ba3CoSb2O9
• High pressure sequence of Ba_3NiSb_2O_9 structural phases: new $S=1$ quantum spin-liquids based on Ni^{2+}
• Covalent bonds against magnetism in transition metal compounds
• Spin liquid behaviour in Jeff=1/2 triangular lattice Ba3IrTi2O9
• Thermal Hall effect in a phonon-glass Ba${}_3$CuSb${}_2$O${}_9$
• Quantum phase diagram of the $S=1/2$ triangular-lattice antiferromagnet Ba${}_3$CoSb${}_2$O${}_9$
• Spin-orbital liquid state assisted by singlet-triplet excitation in $J=0$ ground state of Ba${}_3$ZnIr${}_2$O${}_9$
• Spin--orbital interaction for face-sharing octahedra: Realization of a highly symmetric SU(4) model
• Orbital-dependent singlet dimers and orbital-selective Peierls transitions in transition metal compounds
• Singlet Ground State of the Quantum Antiferromagnet Ba3CuSb2O9
• Evidence for a spinon Fermi surface in the triangular S=1 quantum spin liquid Ba${}_3$NiSb${}_2$O${}_9$
• Spin dynamics in the S =1/2 kagome compound vesignieite, Cu3Ba(VO5H)2
• Charge order at the frontier between the molecular and solid states in Ba3NaRu2O9
• Absence of Jahn-Teller transition in the hexagonal Ba3CuSb2O9 single crystal
• Juxtaposition of Spin Freezing and Long Range Order in a Series of Geometrically Frustrated Antiferromagnetic Gadolinium Garnets
• Competition between supersolid phases and magnetisation plateaux in the frustrated easy-axis antiferromagnet on a triangular lattice

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