Temperature and Ag Doping Effect on Magnetic Excitations in the Quasi-Two-Dimensional Triangular Lattice Antiferromagnet CuCrO₂Studied by Inelastic Neutron Scattering

Exciton-magnon transitions in the frustrated chromium antiferromagnets CuCrO2,α-CaCr2OSchmidt1, Wang2, Kant3 et al. 2013Phys. Rev. B

“…Here T m corresponds to the melting temperature the Z 2 vortices, i.e., the energy scale to overcome the bound-vortex state, and α is a exponent. To check whether this proposal is consistent with our data we use the values for the effective correlation length ξ eff determined in neutronscattering measurements by Kajimoto et al 64 [Fig. 5(a), green circles, right scale].…”

“…Recent high-field electron-spin resonance studies reported two antiferromagnetic-resonance (AFMR) modes with gaps of m 1 = 1.0 cm −1 (0.12 meV) and m 2 = 11 cm −1 (1.4 meV). 63 While the smaller gap has been observed also in neutronscattering studies, 19,64,65 the larger gap has no correspondence in the investigated range of momentum transfer and energy probed in the neutron experiments. However, the energy difference of +13 cm −1 of the magnon sideband from R1 is close in energy to the reported gap and the difference of 2 cm −1 could be due to the fact that ESR and exciton-magnontransition probe spin-wave energies at different points in the Brillouin zone.…”

“…The green circles are data for the inverse of the effective correlation length ξ eff from Ref. 64. Below 18 K the energies of the sideband (stars) and its shoulder (diamonds) are directly read off from the absorption data.…”

Magnetic-field-induced phases in anisotropic triangular antiferromagnets: Application to CuCrO2

“…[3][4][5] The three spins of each triangle form a nearly 120 • structure and all three sublattices form proper-screw spirals that propagate along the same [110] axis with propagation vector q = 0.329 (the spins rotate in and out of the ab plane).[1, 6, 7] The spiral can propagate along any of six directions (three choices for the [110] axis and two choices for the helicity) leading to six possible domains.The proper-screw spiral induces an electric polarization P along the spiral propagation vector. [3,[6][7][8][9][10][11][12] This allows us to probe phase transitions between spiral states at high applied magnetic fields H a , while the magnetization is largely insensitive to these transitions. The non-zero P is consistent with Arima's mechanism for multiferroic behavior, [13] where the spiral magnetic structure slightly influences the hybridization between the Cr d-orbitals and the O p-orbitals via spin-orbit coupling, creating a net P q.…”

Pressure Effect on the Transport and Magnetic Properties for the Hole-Doped Delafossite Oxide CuCr0.97Mg0.03O2 Having an S = 3/2 Antiferromagnetic Triangular Sublattice

“…1) While the compound provides a platform for investigating an effect of geometrical frustration on the magnetic property of the ATL, 1) it has potentials for various applications such as a p-type transparent conductivity, 2) a good thermoelectric response, 3,4) and multiferroics, 5) so the effects of various substitutions on the magnetic, transport, and thermal properties for CuCrO 2 have been extensively investigated. 3,[6][7][8][9] Among various substitutions, the substitution of nonmagnetic Mg 2þ for Cr 3þ effectively increases the electric conductivity and induces a nontrivial effect of the dopedhole on the magnetic and transport properties. According to the specific heat measurements, 6,10) T N increases and the peak of the magnetic specific heat (C mag ) around T N becomes sharper with the Mg substitution, while the substitution of nonmagnetic Al 3þ for Cr 3þ blurs the AF transition.…”