The temperature dependences of the 15N and 133Cs nuclear magnetic resonance spin-lattice times, of the 15N spin-spin relaxation time, and of the 15N and 133Cs spectra, were studied at temperatures of between 209.2 and 673K. A 180 flip of NO2- was found in the low-temperature phase of the material and was deduced to have an associated activation energy of between 8.7 and 11.7kJ/mol. It was noted that the 15N and 133Cs spectra in this phase were inconsistent with the R¯3m structure, and this was attributed to a lower crystal symmetry. A new anionic motion was detected, in the high-temperature phase, which was associated with an activation energy of 11kJ/mol. There was also an isotropic NO2- reorientation with an associated activation energy of between 8.5 and 9kJ/mol, and an ionic self-diffusivity with an activation energy of 47kJ/mol.

H.Honda, M.Kenmotsu, N.Onoda-Yamamuro, H.Ohki, S.Ishimaru, R.Ikeda, Y.Furukawa: Zeitschrift für Naturforschung, 1996, 51A[5-6], 761-8