Frustration-induced nanometre-scale inhomogeneity in a triangular antiferromagnet

Abstract

Phase inhomogeneity of otherwise chemically homogenous electronic systems is an essential ingredient leading to fascinating functional properties, such as high-$T_c$ superconductivity in cuprates, colossal magnetoresistance in manganites, and giant electrostriction in relaxors. In these materials distinct phases compete and can coexist due to intertwined ordered parameters. Charge degrees of freedom play a fundamental role, although phase-separated ground states have been envisioned theoretically also for pure spin systems with geometrical frustration that serves as a source of phase competition. Here we report a paradigmatic magnetostructurally inhomogenous ground state of the geometrically frustrated $\alpha$-NaMnO${}_2$ that stems from the system's aspiration to remove magnetic degeneracy and is possible only due to the existence of near-degenerate crystal structures. Synchrotron X-ray diffraction, nuclear magnetic resonance and muon spin relaxation show that the spin configuration of a monoclinic phase is disrupted by magnetically short-range ordered nanoscale triclinic regions, thus revealing a novel complex state of matter.

version equivalent to the one published in Nature Communications, freely available at http://www.nature.com/ncomms/2014/140129/ncomms4222/full/ncomms4222.html

References in corpus (14)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Fractionalized excitations in the spin liquid state of a kagomé lattice antiferromagnet
• A `checkerboard' electronic crystal state in lightly hole-doped Ca_{2-x}Na_{x}CuO_{2}Cl_{2}
• Lattice symmetry breaking in cuprate superconductors: Stripes, nematics, and superconductivity
• Electronic phase separation in the slightly underdoped iron pnictide superconductor Ba(1-x)K(x)Fe(2)As(2)
• Interplay of Rare Earth and Iron magnetism in RFeAsO with R = La, Ce, Pr, and Sm: A muon spin relaxation study and symmetry analysis
• Charge-cluster glass in an organic conductor
• Orbital degeneracy removed by charge order in triangular antiferromagnet AgNiO2
• Formation of Magnetic Microphases in Ca${}_3$Co${}_2$O${}_6$
• Competing Ferri- and Antiferromagnetic Phases in Geometrically Frustrated LuFe2O4
• Microscopic Evidence of Spin State Order and Spin State Phase Separation in Layered Cobaltites RBaCo2O5.5 with R=Y, Tb, Dy, and Ho
• Microscopic phase separation in triangular-lattice quantum spin magnet kappa-(BEDT-TTF)2Cu2(CN)3 probed by muon spin relaxation
• Persistent spin dynamics intrinsic to amplitude-modulated long-range magnetic order
• Unconventional Magnetism in a Nitrogen-Based Analogue of Cupric Oxide

Cited by in corpus (16)

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• Symmetry Reduction in the Quantum Kagome Antiferromagnet Herbertsmithite
• Experimental signatures of quantum and topological states in frustrated magnetism
• Strain-Induced Extrinsic High-Temperature Ferromagnetism in the Fe-Doped Hexagonal Barium Titanate
• Magnetic inhomogeneity on a triangular lattice: the magnetic-exchange versus the elastic energy and the role of disorder
• Dual Orbital Degeneracy Lifting in a Strongly Correlated Electron System
• Amplitude mode in the planar triangular antiferromagnet Na${}_{0.9}$MnO${}_2$
• Hydration induced spin glass state in a frustrated Na-Mn-O triangular lattice
• Dark Field X-ray Microscopy Below Liquid-Helium Temperature: The Case of NaMnO2
• Nanoscale degeneracy lifting in a geometrically frustrated antiferromagnet
• Decoupling lattice and magnetic instabilities in frustrated CuMnO${}_2$
• Thermal evolution of quasi-1D spin correlations within the anisotropic triangular lattice of $\alpha$-NaMnO${}_2$
• Incommensurate atomic and magnetic modulations in the spin-frustrated β-NaMnO2 triangular lattice
• Floating zone growth of α-Na${}_{0.90}$MnO${}_2$ single crystals
• Magnetic inhomogeneity in the copper pseudochalcogenide CuNCN
• Transient selection of competing order in frustrated spin Peierls systems after a quench