Magnetic ordering in the mixed-valence compound beta-Na0.33V2O5 - art. no.174403

The low-temperature electron spin resonance (ESR) spectra and the static ma gnetization data obtained for the stoichiometric single crystals of beta -N a0.33V2O5 indicate that this quasi-one-dimensional mixed-valence compound d emonstrates at T-N = 22 K the phase transition into the canted antiferromag netically ordered state. The spontaneous magnetization of 3.4x10(-3) mu (B) per V4+ ion was found to be oriented along the twofold b axis of the monoc linic structure, the vector of antiferromagnetism is aligned with the a axi s and the Dzyaloshinsky vector is parallel to the c axis. The experimental data were successfully described in the frame of the macroscopic spin dynam ics and the following values for the macroscopic parameters of the spin sys tem were obtained: the Dzyaloshinsky field H-D = 6 kOe and the energy gaps of two branches of the spin wave spectrum Delta (1)/(2 pi) = 48 GHz and Del ta (2)/(2 pi) = 24 GHz.