Phase Transitions, Thermal Expansions, Chemical Expansions, and CO2 Resistances of Ba(Ce0.8-xZrxY0.1Yb0.1)O3-δ (x = 0.1, 0.4) Perovskite-Type Proton Conductors. Issue 2 (1st February 2022)

• Record Type: Journal Article
• Authors: Nomura, Katsuhiro; Shimada, Hiroyuki; Yamaguchi, Yuki; Shin, Woosuck; Okuyama, Yuji; Mizutani, Yasunobu
• Is Part Of: Journal of the Electrochemical Society. Volume 169:Issue 2(2022)
• Publication Date: 2022-02-01
• Subjects: Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/1945-7111/ac5480
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : The phase transitions, thermal expansions, chemical expansions, and CO2 resistances of Ba(Ce0.7 Zr0.1 Y0.1 Yb0.1 )O3- δ (BCZYYb7111) and Ba(Ce0.4 Zr0.4 Y0.1 Yb0.1 )O3- δ (BCZYYb4411) have been investigated via high-temperature X-ray diffraction in controlled atmospheres (dry N2, wet N2, and dry 33.3 vol% CO2 − 66.6 vol% N2 ) on cooling from 1173 to 298 K. Two phase transitions (cubic ( Pm 3 ¯ m ) to trigonal ( R 3 ¯ c ) and trigonal ( R 3 ¯ c ) to monoclinic ( I 2/ m )) were observed for BCZYYb7111, whereas one phase transition (cubic ( Pm 3 ¯ m ) to trigonal ( R 3 ¯ c )) was observed for BCZYYb4411 when the samples were prepared at 1873 K in air. Dehydrated BCZYYb7111 and BCZYYb4411 (by firing at 1273 K for 10 h in dry N2 ) showed trigonal ( R 3 ¯ c ) and cubic ( Pm 3 ¯ m ) symmetries, respectively, at 298 K in dry N2 . BCZYYb7111 and BCZYb4411 exhibited linear thermal expansion coefficients (LTECs) of 10.7 × 10 −6 K −1 and 10.1 × 10 −6 K −1, respectively, from 973 to 1173 K in dry N2 and maximum chemical expansion rates (CERs) of 0.33% and 0.29%, respectively, at 773 K. BCZYYb7111, which has a higher Ce/Zr ratio, exhibited larger LTEC and CER values than BCZYYb4411, whereas BCZYYb4411, which has a lower Ce/Zr ratio, exhibited higher CO2 resistance than BCZYYb7111.