The different amount of Fe atoms was deposited by controlling the deposition time. After the deposition of Fe atoms, the Fe/Si(111)-7 × 7-C2H5OH sample was translated into the main chamber for STM observation. In order to know the chemical stability

of the sample, the sample was exposed to the thin-air condition with 4.5 × 10-2 Langmuir (~10-2 L for O2) in Luminespib the main chamber by the needle valve. Before and after the exposing, the Fe/Si(111)-7 × 7-C2H5OH sample was translated into the composition test chamber, respectively, where the sample was in situ tested by the GammadataScienta SES-100 X-ray photoelectron spectroscopy (XPS) system (Pleasanton, CA, USA). In our experiments, the XPS spectra were in situ performed with an Al kα line source (hv = 1,486.6 eV) at an incident angle of 45°. Before the measurement, the XPS system was

calibrated by the standard Au and Cu samples. In consideration of the signal-to-noise ratio of data, the area of XPS measurement was kept as 100 μm in diameter for all tests. Then, the high-resolution spectra were recorded with 29.35 and 0.125 eV in the pass energy and step, respectively. Cell Cycle inhibitor All spectra were referenced to C 1 s peak of 284.6 eV. Results and discussion Figure 1a shows the typical STM image of Si(111)-7 × 7-reconstructed surface with 55 × 55 nm2, where the inset was the high magnification with 10 × 10 nm2. In the inset of Figure 1a, each triangular half unit cell contains six Si ad-atoms, which are shown as the bright dots. Figure 1b shows the standard Si(111)-7 × 7-C2H5OH surface with 25 × 25 nm2 and 0.5 mono layer (ML). In Figure 1b, each triangular half unit cell

contains three Si ad-atoms and three Si-OC2H5, which the Si ad-atoms show as the bright dots and Si-OC2H5 is not shown in the STM image. From Figure 1, it can be confirmed that the Si(111)-7 × 7 and Si(111)-7 × 7-C2H5OH surface has been prepared by our standard heating, flashing, and saturating procedures [10–13]. Figure 1 Typical and standard STM image of Si(111)-7 × 7-reconstructed surface. The typical STM image of Si(111)-7 × 7-reconstructed surface find more (a), where the inset was the high magnification. And the standard Si(111)-7 × 7-reconstructed surface saturated by C2H5OH (b). During all scanning process, the bias voltage and Alvocidib mw tunneling current was kept at 1.5 V and 0.19 nA, respectively. The STM images of Fe clusters formed on Si(111)-7 × 7-C2H5OH surface are shown in Figure 2. From Figure 2a, it can be seen that with 0.01 ML Fe atom deposition, a few of Fe clusters are randomly formed on the Si(111)-7 × 7-C2H5OH surface, instead of dispersed single Fe atoms. From the inset of Figure 2a, it can be recognized that a Fe cluster having six Fe atoms is formed and the cluster looks to take a pentagonal base pyramid structure [14, 15].