Influence of Mg, Ag and Al substitutions on the magnetic excitations in the triangular-lattice antiferromagnet CuCrO2

Abstract

Magnetic excitations in CuCrO${}_2$, CuCr${}_{0.97}$Mg${}_{0.03}$O${}_2$, Cu${}_{0.85}$Ag${}_{0.15}$CrO${}_2$, and CuCr${}_{0.85}$Al${}_{0.15}$O${}_2$ have been studied by powder inelastic neutron scattering to elucidate the element substitution effects on the spin dynamics in the Heisenberg triangular-lattice antiferromagnet CuCrO${}_2$. The magnetic excitations in CuCr${}_{0.97}$Mg${}_{0.03}$O${}_2$ consist of a dispersive component and a flat component. Though this feature is apparently similar to CuCrO${}_2$, the energy structure of the excitation spectrum shows some difference from that in CuCrO${}_2$. On the other hand, in Cu${}_{0.85}$Ag${}_{0.15}$CrO${}_2$ and CuCr${}_{0.85}$Al${}_{0.15}$O${}_2$ the flat components are much reduced, the low-energy parts of the excitation spectra become intense, and additional low-energy diffusive spin fluctuations are induced. We argued the origins of these changes in the magnetic excitations are ascribed to effects of the doped holes or change of the dimensionality in the magnetic correlations.

arXiv comment7 pages, 5 figures

References in corpus (6)

• Nonmagnetic Insulating States near the Mott Transitions on Lattices with Geometrical Frustration and Implications for $\kappa$-(ET)${}_2$Cu${}_2(CN{)}_3$
• Gapless quantum spin liquid, stripe and antiferromagnetic phases in frustrated Hubbard models in two dimensions
• Spin dynamics in the geometrically frustrated multiferroic CuCrO2
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• Signature of a Z_2 vortex in the dynamical correlations of the triangular-lattice Heisenberg antiferromagnet
• Spin dynamics in triangular lattice antiferromagnets CuCr${}_{1-x}$Mg${}_x$O${}_2$

Cited by in corpus (1)

• Development of spin correlations in the geometrically frustrated triangular-lattice Heisenberg antiferromagnet CuCrO2