Study of proton conduction in thulium-doped barium zirconates at high temperatures

The specimens of BaZr1-xTmxO3-alpha (x = 0.02, 0.05, 0.10 and 0.15, alpha = x/2) have been prepared and characterized. The formation of the single per ovskite phase in the samples was checked by x-ray diffraction. For the veri fication of the possible charge carriers in the sintered BaZr1-xTmxO3-alpha samples, three different electrochemical cell measurements were carried ou t. The measurements of electromotive force (emf) of hydrogen and steam conc entration cells showed that the BaZr1-xTmxO3-alpha ceramic is a protonic co nductor and the measurements of emf of the oxygen concentration cell showed that the BaZr0.90Tm0.10O3-alpha sample exhibited poor oxide ion conduction . Proton transport number IH was calculated and was found to be dependent o n the content, I. The BaZr0.90Tm0.10O3-alpha, sample showed the highest val ue of proton transport number in the temperature range 500 less than or equ al to T less than or equal to 900 degreesC.