High temperature proton NMR study of yttrium doped barium cerates

The mobility of protons in BaCe1−xYxO3−δ perovskite (x=0.01 to 0.10) was investigated by high temperature 1H NMR spin-lattice relaxation time (T1) and ac conductivity measurements. The temperature variation of T1 was obtained from room temperature to 1073 K. The absolute magnitude of T1 shows a complex dependence on doping concentration. However, the shape of the temperature dependence of T1 was independent of the doping concentration, suggesting the absence of major differences of the proton hopping mechanism on doping level of this material. The measured conductivity was well reproduced by a simple hopping model using correlation times of proton migration and proton concentrations estimated from the NMR measurement.