Preparation of Dense Ba1−xSrxZr1−yYyO3−δ (y = 0.0, 0.1) Ceramics by Pechini Method

Ba1−xSrxZrO3, which is the mother phase of proton-conducting Ba1−xSrxZr0.9Y0.1O3−δ, is prepared by the Pechini method at a sintering temperature of 1500°C. For specimens with x ≥ 0.4, the sintering densities of the samples prepared by the Pechini method are approximately 90%, whereas those of the samples prepared by the solid-state reaction method are approximately 78%. Although the difference in the mean grain size was small, clear facets are observed around the grains of the Ba0.6Sr0.4ZrO3 ceramic prepared by the Pechini method and grain size distribution is less than that of the Ba0.6Sr0.4ZrO3 ceramics prepared by the solid-state reaction method. The smaller grain size distribution is attributed to the formation of a Ba0.6Sr0.4ZrO3 phase with smaller grains upon calcination at a temperature as low as 800°C by the Pechini method due to the homogeneous cation distribution in the precursor. Not only a decrease in the number of pores but also an increase in the grain size is observed with increasing Sr content in Ba1−xSrxZr0.9Y0.1O3−δ, resulting in a sintering density as high as 92% for Ba0.6Sr0.4Zr0.9Y0.1O3−δ.