Effect of Chemical Composition on the Nanoscale Ordering Transformations of Physical Mixtures of Pd and Cu Nanoparticles

Figure 4

(a) TEM image of the PdCu 1 : 1 nanoparticle mixture after ramp annealing at 750°C on the SiO₂/Si substrate in a forming gas atmosphere. (b) High-resolution image of the PdCu particle marked in (a) reveals uniform lattice fringes across the particle with an interplanar distance of 2.19 Å that corresponds to the [111] plane of the Alloy-1 phase. (c) The FFT from a marked area in (b) is indexed as the [211] zone axis of the PdCu Alloy-1 phase. (e) High-resolution image of another PdCu particle marked in (a) reveals uniform lattice fringes across the particle with an interplanar distance of 1.93 Å that corresponds to the [002] plane of the Alloy-2 phase. (d) The FFT from a marked area in (e) is indexed as the [110] zone axis of the PdCu Alloy-2 phase. Scale bars are 5 nm for images (a), (b), and (e).