Improving the mechanical performance of nanocrystalline functional oxides can have major implications for stability and resilience of battery cathodes, development of reliable nuclear oxide fuels, strong and durable catalytic supports. By combining Monte Carlo simulations, experimental thermodynamics, and in-situ transmission electron microscopy, we demonstrate a novel toughening mechanism based on interplay between the thermo-chemistry of the grain boundaries and crack propagation. By using zirconia as a model material, lanthanum segregation to the grain boundaries was used to increase the toughness of individual boundaries and simultaneously promote a smoother energy landscape in which cracks experience multiple deflections through the grain boundary network, ultimately improving fracture toughness.

改善纳米晶体功能性氧化物的机械性能可能对电池阴极的稳定性和回弹力，开发可靠的核氧化物燃料，坚固耐用的催化载体产生重大影响。通过结合蒙特卡洛模拟，实验热力学和原位透射电子显微镜，我们展示了一种新的增韧机理，基于晶界的热化学和裂纹扩展之间的相互作用。通过使用氧化锆作为模型材料，镧偏析到晶界被用来增加单个晶界的韧性，同时促进更平滑的能量分布，其中裂纹在晶界网络中经历多次挠曲，最终提高了断裂韧性。