We report the direct observation of oxide ion dynamics on both nano- and picosecond timescales in the isostructural Bi₂O₃-derived solid electrolytes Bi_0.852V_0.148O_1.648 and Bi_0.852P_0.148O_1.648 using quasielastic neutron scattering. Comprehensive ab initio molecular dynamics simulations allowed us to reproduce the experimental picosecond timescale data by directly simulating the scattering function at various temperatures. Our analysis of the experimental data in conjunction with the simulations revealed the origin of the picosecond dynamics to be localized motions within the V–O and P–O sublattices, while nanosecond dynamics correspond to the diffusion of the oxide ions in the Bi–O sublattice via vacancy-hopping. This combined approach provides insight into the different oxide ion migration pathways and mechanisms in Bi_0.852V_0.148O_1.648 and Bi_0.852P_0.148O_1.648, with the flexibility of the V coordination environment playing an important role, consistent with the superior conductivity of the vanadate.

中文翻译：

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V 和 P 掺杂 Bi2O3 基固体电解质中的氧离子迁移率：将准弹性中子散射与从头算分子动力学相结合

_{我们报告了在同构 Bi 2} O ₃衍生的固体电解质 Bi _0.852 V _0.148 O _1.648和 Bi _0.852 P _0.148 O _1.648中在纳秒和皮秒时间尺度上直接观察氧化物离子动力学使用准弹性中子散射。全面的从头算分子动力学模拟使我们能够通过直接模拟不同温度下的散射函数来重现实验皮秒时间尺度数据。我们结合模拟对实验数据的分析揭示了皮秒动力学的起源是 V-O 和 P-O 子晶格内的局部运动，而纳秒动力学对应于氧化离子在 Bi-O 子晶格中的扩散通过跳空。_{这种组合方法提供了对 Bi 0.852} V _0.148 O _1.648和 Bi _0.852 P _0.148 O _1.648中不同氧化物离子迁移途径和机制的深入了解，随着 V 配位环境的灵活性发挥重要作用，与钒酸盐的优异导电性一致。