Synthesis and Triple Conductive Properties of Ba and Fe Co-Doped Sr2TiO4 Based Layered Perovskite: (BaxSr2-x) (Ti0.9Fe0.1)O4-δ (X= 0.05, 0.10)

This study investigated the effects of Ba substitution on protonic conductive properties in the Fe doped Sr2TiO4 layered perovskite. We synthesized sintered samples of (BaxSr2-x)(Ti0.90Fe0.10)O4-δ (x= 0.05, 0.10) (BSTF05, BSTF10). The result of X-ray diffraction suggests that solid solute limitation of Ba is between x= 0.05 and 0.10. BSTF05 at 600 °C shows proton and oxide-ion conductivities as well as elecronic conductivity. It means that BSTF05 is a triple conductor at 600 °C under oxidation atmosphere. The proton conductivities in BSTF05 are lower than that in Ba un-doped Sr2(Ti0.9Fe0.1)O4-δ evaluated in our previous work, suggesting that the effect of the Ba substitution on proton defect generation is small. The redox reaction of Fe ions is more important for creation of proton defects in the layered perovskites.

Soliton model for collective proton transfer in extended realistic hydrogen-bonded systems

The discretized version of the collective proton transfer in extended one-dimensional hydrogen-bonded systems with the Lippincott-Schroeder potential is studied. A discrete quasi-kink is compared with its continuum approximation ‘image’. The Peierls-Nabarro activation energy of diffusion of collective proton defect is estimated. The concept of local proton potentials is introduced on the background of the kink-carrier collective variable.