The platinum islands were annealed in the furnace for 10 min at 1,000°C in nitrogen flow to protect them from oxidation. Cubooctahedral facetted particles form on (100) STO
substrate [2]. Figure 4 shows SEM image of arrays of platinum nanoparticles Ralimetinib molecular weight prepared with 450- and 150-nm silica bead masks. The larger and smaller silica masks produced approximately 100-nm and approximately 20-nm platinum nanoparticles, respectively. The entire process is schematically shown in the Figure 5. Figure 2 AFM images of monolayers from silica beads with diameter (a) 150 nm and (b) 450 nm. Imaged areas are 8 × 8 μm2 and 25 × 25 μm2, respectively. Figure 3 AFM image of platinum nanoislands deposited through voids in template from hexagonally packed 450-nm silica beads. Scanned area is equal to 3.5 × 3.5 μm2. Figure 4 SEM images of platinum nanocrystals. The crystals are arranged in hexagonal patterns produced using 450-nm (a) and 150-nm (b) silica bead templates. Insets: top right corner, rendered particle; bottom right corners, digital zooms of actual cubooctahedral nanocrystals with
clearly visible top 100 facets and four 111 facets on the sides. Distortion of hexagonal arrangement of nanocrystals in (b) is caused by the sample drift at high magnifications. Figure 5 Schematic diagram summarizing production of arrays of platinum cubooctahedral nanoparticles on STO substrates. X-ray characterization of Pt arrays on STO We performed X-ray diffraction (XRD) characterization of prepared nanoparticle arrays in order to prove the epitaxial relationship between check details particles and the STO substrate. The X-ray diffraction results for Pt nanoparticle arrays made using 150- and 450-nm silica bead this website templates are shown in Figure 6a,b, respectively. In both
cases, there exists a Pt (004) reflection on the shoulder of specular STO (004); thus, the Pt nanocrystals have a surface normal to (001) facet, which agrees with Pt nanoparticles prepared by e-beam lithography [2] on STO (100). Because the peaks sit on the shoulder of strong reflection from STO, it is difficult to precisely estimate the width of the platinum peak. Oxymatrine Figure 6 θ -2 θ scans. θ-2θ scans of Pt (004) for (a) 150-nm and (b) 450-nm samples showing that Pt (004) is parallel to the substrate’s normal reflection. Insets show SEM images of the platinum particles after annealing (the hexagonal grids are guides to the eyes). In order to show in-plane epitaxial orientation of Pt nanoparticles, we performed scans in the HK directions. Figure 7 shows Pt (113) peak on the shoulder of the STO (113). The ϕ scans (constant L) shown in the insets of Figure 7a,b show that equivalent Pt (113) peaks occur every 90°, as expected, and no other Pt peaks are found in the ϕ scans. Figures 6 and 7 together show that the Pt nanocrystals are indeed epitaxially deposited onto the STO substrate. Figure 7 ϕ scans.