Department of Applied Physics, Nanjing University of Science and Technology, Nanjing 210094, China.
Phys Chem Chem Phys. 2013 Feb 28;15(8):2692-7. doi: 10.1039/c2cp43350h. Epub 2013 Jan 22.
Density functional theory calculations and first-principles molecular dynamics (MD) simulations have been performed to examine the strain effect on the colossal oxygen ionic conductivity in selected sandwich structures of zirconia electrolytes. For the KTaO(3)/YSZ/KTaO(3) sandwich structure with 9.7% lattice mismatch, transition state calculations indicate that the strain effect changes the oxygen migration pathways from straight line into zigzag form and reduces the energy barrier by 0.2 eV. On the basis of our computational results, a possible oxygen ion diffusion highway is suggested. By finite-temperature MD simulations, an activation barrier of 0.33 eV is obtained, corresponding to an oxygen ionic conductivity which is 6.4 × 10(7) times higher than that of the unstrained bulk zirconia at 500 K. A nearly linear relationship is identified between the energy barrier and the lattice mismatch in the sandwich structures.
采用密度泛函理论计算和第一性原理分子动力学（MD）模拟研究了应变对选定的氧化锆电解质夹层结构中巨氧离子电导率的影响。对于晶格失配为 9.7%的 KTaO(3)/YSZ/KTaO(3)夹层结构，过渡态计算表明应变效应将氧迁移路径从直线变为之字形，并将能垒降低了 0.2 eV。基于我们的计算结果，提出了一种可能的氧离子扩散高速公路。通过有限温度 MD 模拟，得到了 0.33 eV 的激活势垒，对应于 500 K 时未应变体氧化锆的氧离子电导率高 6.4×10(7)倍。在夹层结构中，能量势垒与晶格失配之间存在近似线性关系。
