School for Engineering of Matter, Transport and Energy, Arizona State University, 501 E. Tyler Mall, Tempe, Arizona 85287-6106, USA.
Nanoscale. 2017 Nov 16;9(44):17293-17302. doi: 10.1039/c7nr06941c.
The enhancement of oxygen ionic conductivity by over two orders of magnitude in an electroceramic oxide is explicitly shown to result from nanoscale enrichment of a grain boundary layer or complexion with high solute concentration. A series of CaCeO polycrystalline oxides with fluorite structure and varying nominal Ca solute concentration elucidates how local grain boundary composition, rather than structural grain boundary character, primarily regulates ionic conductivity. A correlation between high grain boundary solute concentration above ∼40 mol%, and four orders of magnitude increase in grain boundary conductivity is explicitly shown. A correlated experimental approach provides unique insights into fundamental grain boundary science, and highlights how novel aspects of nanoscale grain boundary design may be employed to control ion transport properties in electroceramics.
电陶瓷氧化物中氧离子电导率通过两个数量级的提高被明确证明是由于纳米级的晶粒边界层或复合层中高溶质浓度的富集。一系列具有萤石结构和不同名义 Ca 溶质浓度的 CaCeO 多晶氧化物阐明了局部晶粒边界组成，而不是结构晶粒边界特性，主要调节离子导电性。高晶粒边界溶质浓度（高于约 40mol%）与晶粒边界电导率四个数量级的提高之间存在明确的相关性。一种相关的实验方法提供了对基本晶粒边界科学的独特见解，并强调了如何利用纳米级晶粒边界设计的新颖方面来控制电陶瓷中的离子输运特性。
