NMR measurements on proton conductor CsHSeO4 below Tc = 401 K

The temperature dependence of 1H-NMR absorption line of CsHSeO4 has been measured with external magnetic field applied parallel to the b axis of room temperature phase in the temperature range of 77–410 K. The NMR absorption line of 77 K, which is described with the Gaussian curve, has a single peak and the line width of ~ 1.8 G. The NMR absorption line at 261 K obviously consists of the two absorption lines with different line widths. The one of two NMR absorption lines of 261 K, which has shaper line width than that of 77 K, is good agreement with the Lorentzian curve. This result indicates that hopping protons exist even below Tc = 401 K. Moreover it is clarified from the temperature dependence of the area of the Lorentzian curve to the total NMR absorption RL that two kinds of phase of activated proton exist even below superionic phase.