Element-specific quantitative determination of the local atomic order in CoPt alloy nanoparticles: Experiment and theory

Article

关键词: RAY-ABSORPTION SPECTROSCOPY;    OXYGEN REDUCTION REACTION;    TOTAL-ENERGY CALCULATIONS;    AUGMENTED-WAVE METHOD;    MAGNETIC-ANISOTROPY;    PHASE-TRANSITION;    BASIS-SET;    SIZE;   

DOI  :  10.1103/PhysRevB.87.155412

来源: SCIE

【 摘 要 】

An annealing-driven transition from a chemically disordered A1-like structure to a chemically ordered L1(0)-like phase has been revealed for size-selected CoPt clusters with diameters from 2 to 4 nm, from experiment to theory confrontation. For chemically ordered particles, atypical lattice-parameter ratios c/a are inferred. This ratio is found to be remarkably different depending on the approach used (c/a > 1 from x-ray absorption at the Co K edge and c/a similar or equal to 0.94 from the Pt dominated x-ray diffraction). A first-principles theoretical study accurately explains this astonishing feature and provides a detailed understanding of the element-specific local relaxations, which are crucial in these nanoalloys. DOI: 10.1103/PhysRevB.87.155412

【 授权许可】

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