EPR APPLICATION IN THE STUDY OF K3H(SO4)2 PROTON CONDUCTOR DOPED WITHMN2+ OR VO2+ IONS

The EPR of Mn2+- or VO2+-doped superprotonic conductor K3H(SO4)2 is st udied in the 80-471 K temperature range. VO2+ EPR spectrum reveals dif fusion induced merging of proton transferred superhyperfine structure above 380 K. Line width anomaly is observed in Mn2+ EPR spectrum which is attributed to the intrabond and interbond proton motions, these le ad to high protonic conductivity. It is shown that paramagnetic center s namely of electronic spin greater than 1, with excess charge compens ated by the protonic vacancy, are good probes to monitor the protonic conductivity on molecular level.