Grain Boundary Space Charge Effect and Proton Dynamics in Chemically Stable Perovskite‐Type Ba 0.5 Sr 0.5 Ce 0.6 Zr 0.2 Gd 0.1 Y 0.1 O 3−δ ( BSCZGY ): A Case Study on Effect of Sintering Temperature

• Published in: Journal of the American Ceramic Society 2016-03, Vol.99 (3), p.866-875
• Main Authors: Singh, Kalpana, Baral, Ashok Kumar, Thangadurai, Venkataraman
• Format: Article
• Language: English
• ISSN: 0002-7820; 1551-2916
• DOI: 10.1111/jace.14008

The present study reports the effect of sintering temperature on the proton dynamics of perovskite‐type Ba 0.5 Sr 0.5 Ce 0.6 Zr 0.2 Gd 0.1 Y 0.1 O 3−δ ( BSCZGY ) by establishing a co‐relation between the grain‐boundary ( GB ) space charge effect, electrical conductivity and dielectric loss of the BSCZGY samples sintered at 1300°C, 1400°C, and 1550°C for 20 h in air. Although, the GB s are the main source of resistance in BaZrO 3 based ceramic proton conductors, we show that the GB impedance disappeared above 450°C and 300°C, respectively, for BSCZGY samples sintered at 1300°C and 1400°C. Interestingly, the BSCZGY sample sintered at 1550°C showed absence of GB contribution to total conductivity even at 200°C. The GB electrostatic potential [ϕ(0)] was found to vary between 0.35–0.38 V and 0.4–0.45 V, respectively, for the samples sintered at 1300°C and 1400°C at 200°C–300°C. The migration energy ( E m ) of the protons was found to be 0.71, 0.65 and 0.58 eV for the sample sintered at 1300°C, 1400°C and 1550°C, respectively.