Exchange splitting inCuGeO3under ultrahigh magnetic fields

Abstract

Electron paramagnetic resonance has been observed on CuGeO 3 in ultrahigh magnetic fields up to 180 T. The distinct exchange splitting is found between the two inequivalent Cu 2ϩ sites along the b axis. Analyzing the data on the basis of a simple two-spin model, we evaluated the interchain exchange coupling J b as ϳ0.9 meV. This value is a little smaller than J b ϳ1.0 meV obtained by neutron-scattering experiments.

Field-induced structural evolution in the spin-Peierls compoundCuGeO3:High-field ESR study

“…The Lorentzian fit of absorptions was used to calculate the ESR linwidth at half-height. The gfactor of excitations remains almost constant in the entire frequency-field range, g ∼ 2.15, which is consistent with pulsed-field ESR data 6 . However, a drastic change in the ESR linewidth ∆B is observed at the transition from the dimerized to incommensurate phase.…”

Cu63nuclear relaxation in the spin-Peierls compound CuGeOItoh1, Sugahara2, Yamauchi3 et al. 1996Phys. Rev. B154190View full textAdd to dashboardCite

“…11͒ by theoretical analyses of the magnetic susceptibility, 120 K by the inelastic neutron-scattering measurement, 12 and 183 K by the magnetization study in ultra-high magnetic fields. 13 Previously, it was pointed out that the overall-T dependence of 1/T 1 measured above T SP up to 80 K for 63 Cu nuclear quadrupole resonance ͑NQR͒ in CuGeO 3 may be understood by the 1DHAF model. 14,15 However, this has not been confirmed up to now.…”

Direct Determination of Exchange Parameters inCs2CuBr4andCs2<

“…The proposed approach can be used for accurate estimation of exchange parameters of a growing family of spin-1=2 triangular-lattice AFs, including organic compounds (see [10][11][12][13] and references therein); those investigations via conventional neutron-scattering techniques are rather challenging. The employment of very high magnetic fields (up to ca 70 T [34,35] and above [36][37][38], currently available for pulsed-field magnetospectroscopy) as well as the rapid progress in the THz techniques makes the proposed method of crucial importance for investigating spin systems with large J=k B . The approach has a broader impact and can be potentially used for any quantum magnet with reduced (e.g., by the staggered DM interaction) translational symmetry, resulting, as predicted, in emergence of a new exchange mode above H sat .…”