High proton conductivity in barium yttrium stannate Ba2YSnO5.5

✍ Scribed by P Murugaraj; K.D Kreuer; T He; T Schober; J Maier

• Book ID: 104296659
• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 370 KB
• Volume: 98
• Category: Article
• ISSN: 0167-2738
• DOI: 10.1016/s0167-2738(97)00102-1

✦ Synopsis

Ba YSnO

is found to crystallize in a perovskite structure with a 5 848 pm. The compound may be hydrated 2 5.5 21 21 21 8 8 ( D H 5 2 101.5 kJ mol , DS 5 2 92.5 J mol K ) to a high degree (maximum water content 5 13.5 mol%) hydr. hydr. ? which leads to the formation of protonic charge carriers (OH ) and the occurrence of very high proton conductivity with low O activation enthalpy (E 5 0.51 eV) comparable to that of BaCeO based materials which are the oxides with the highest a 3 ?? ?

proton conductivities reported so far. The conductivity contributions from native ions (V , h ) are found to be negligible for O temperatures below 6008C. In contrast to BaCeO based materials Ba YSnO shows good chemical durability with respect 3 2 5 . 5

to carbonate formation. However, structural instability becomes apparent in a high grain boundary impedance, a collapse of the structure upon reduction and the macrocracking induced by lattice strain resulting from hydration.