SITE IDENTIFICATION OF PROTONS IN SRTIO3 - MECHANISM FOR LARGE PROTONIC CONDUCTION

It is found that the proton is strongly absorbed in heavily Sc-doped S rTiO3. Neutron-diffraction measurements were performed using single cr ystals. The O-H distance is found to be about 1.2 Angstrom and the pro ton concentration is estimated to be about 2 mol% for SrTi0.98Sc0.02O3 . Protonic conduction was observed in Sc-doped SrTiO3 by ac-conductivi ty measurements in wet air, while the hole conductivity was observed i n dry air. The proton is bound by the oxygen ion as if the proton make s the hydrogen bond between two oxygen ions, which might be responsibl e for the high protonic conductivity in this material.