Magnetic inhomogeneity on a triangular lattice: the magnetic-exchange versus the elastic energy and the role of disorder

Abstract

Inhomogeneity in the ground state is an intriguing, emergent phenomenon in magnetism. Recently, it has been observed in the magnetostructural channel of the geometrically frustrated $\alpha$-NaMnO${}_2$, for the first time in the absence of active charge degrees of freedom. Here we report an in-depth numerical and local-probe experimental study of the isostructural sister compound CuMnO${}_2$ that emphasizes and provides an explanation for the crucial differences between the two systems. The experimentally verified, much more homogeneous, ground state of the stoichiometric CuMnO${}_2$ is attributed to the reduced magnetoelastic competition between the counteracting magnetic-exchange and elastic-energy contributions. The comparison of the two systems additionally highlights the role of disorder and allows an understanding of the puzzling phenomenon of phase separation in uniform antiferromagnets.

arXiv commentPublished version, freely available at http://www.nature.com/srep/2015/150319/srep09272/full/srep09272.html

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Cited by in corpus (12)

• Quantum Magnetism in Minerals
• Symmetry Reduction in the Quantum Kagome Antiferromagnet Herbertsmithite
• Negative-vector-chirality 120${}^{\circ }$ spin structure in the defect- and distortion-free quantum kagome antiferromagnet YCu${}_3$(OH)${}_6$Cl${}_3$
• Development of short and long-range magnetic order in the double perovskite based frustrated triangular lattice antiferromagnet Ba2MnTeO6
• Hydration induced spin glass state in a frustrated Na-Mn-O triangular lattice
• Nanoscale degeneracy lifting in a geometrically frustrated antiferromagnet
• Thermodynamic model of a solid with RKKY interaction and magnetoelastic coupling
• Thermal evolution of quasi-1D spin correlations within the anisotropic triangular lattice of $\alpha$-NaMnO${}_2$
• Self-consistent model of a solid for the description of lattice and magnetic properties
• Decoupling lattice and magnetic instabilities in frustrated CuMnO${}_2$
• Incommensurate atomic and magnetic modulations in the spin-frustrated β-NaMnO2 triangular lattice
• Magnetic inhomogeneity in the copper pseudochalcogenide CuNCN