FAR-INFRARED PROPERTIES AND MAGNETIC EXCITATIONS IN PRBA2CU3O6

Dynamic properties and magnetic excitations in PrBa2Cu3O6 were investi gated by means of a quasi-optical submillimeter backward-wave-oscillat or technique and a Fourier spectrometer at the wavelengths nu = 4-33 a nd 50-650 cm(-1) respectively. A weak and wide absorption line was obs erved in the submillimeter transmission spectra near 15 cm(-1) at T < 70 K, which was identified as a rare-earth mode originating from elect ronic transitions between the low-energy crystal-field states of Pr3+. Temperature dependence of the resonance frequency, linewidth and mode contribution to static magnetic permeability were obtained. Dynamic m agnetic susceptibility chi(omega, q, T) and resonance frequencies omeg a(q, T) of the magnetic excitations of the Pr-subsystem were calculate d and analyzed above and below the Neel temperature (T-N = 10 K). (C) 1998 Elsevier Science B.V. All rights reserved.