In order to determine the stoichiometry of the c (4 × 8) thin film, we performed a curve fitting on the spectrum and the result of the fit is also included in the figure. In the fitting procedure, the spin-orbit splitting was fixed at 0.6 eV for all components. The Si 2p spectrum can

be decomposed into two components, with the main component C1 at E B = 99.2 eV (2p 3/2 line) and the other component C2 at E B = 99.5 eV. The C1 component comes from the contribution of Si substrate, while the C2 is associated with the iron silicides formed on the Si substrate. Compared to the bulk Si component, the Si 2p peak for the Fe silicides has shifted to a higher binding energy (+0.3 eV) and the FWHM has become wider (+0.4 eV), which is consistent with that reported Savolitinib in the previous studies [21, 22]. Quantitative analysis of the XPS data shows that the atomic ratio of Fe/Si in the c (4 × 8) thin film is approximately 1:2.05, indicating that the c (4 × 8) thin film phase is in the FeSi2 stoichiometry regime. Figure 6 XPS Si 2 p spectrum for the c (4 × 8) thin film grown on the Si (111) substrate. The open circles represent the experimental data and the thick solid line (red) overlapping them is the fit to the data. The right side peak can be decomposed into C1 and C2 components. The main component C1 comes from the contribution of Si substrate,

while component C2 comes from the contribution of the iron silicide phase. The residual of the fit is shown by the lowermost solid line (black). Conclusions In VX-689 datasheet summary, using RDE method, we have shown that a homogeneous crystalline iron silicide thin film of c (4 × 8) phase can be grown on the Si (111) surface at a temperature above approximately 750°C. The thickness of the c (4 × 8) film can be up to approximately 6.3 Å. This result is quite different from the previous Niclosamide results obtained using the

SPE method, where the c (4 × 8) film has a definite thickness in the range of 1.4 to 1.9 Å. We attribute the larger thickness of the c (4 × 8) film obtained by the RDE method to the AZD1152 cost supply of sufficient free Si atoms during the silicide reaction. Scanning tunneling spectroscopy measurements show that the c (4 × 8) thin film exhibits a semiconducting character with a band gap of approximately 0.85 eV. Quantitative XPS analysis shows that the c (4 × 8) phase is in the FeSi2 stoichiometry regime. This homogeneous c (4 × 8) thin film could be used in the optoelectronic devices or serve as a precursor surface applicable in magnetic technological fields. Acknowledgements This work was supported by the National Natural Science Foundation of China under grant no. 61176017 and the Innovation Program of Shanghai Municipal Education Commission under grant no. 12ZZ025. References 1. Walter S, Bandorf R, Weiss W, Heinz K, Starke U, Strass M, Bockstedte M, Pankratov O: Chemical termination of the CsCl-structure FeSi/Si (111) film surface and its multilayer relaxation. Phys Rev B 2003, 67:085413.CrossRef 2.

53 nm wide. Analysis of the Fourier spectra from Figure 5a,b showed periods of 0.2, 0.14, and 0.12 nm in the structure of the alloy (Figure 8). This is likely due to β-W Selumetinib molecular weight (ICSD 52344). Because of the phases for Ni, W, and their combinations, β-W is the only one with the appropriate lattice parameter. We assumed that, on a free surface, growth occurs by increments on one elementary cell. Unfortunately, in this case, the nanocrystal orientation was such that the atomic planes parallel to the free

surface could not be seen. Accordingly, the volume of material transferred in 60 s was anywhere from 0.84 to 1.68 nm3. The volume of an elementary cell of β-W is 0.12879 nm3, meaning that between 6 and 13 elementary cells, 48 to 104 atoms were deposited in 60 s. The coefficient of this website diffusion ranged from 0.9 to 1.7 × 10−18 m2/s. Figure 8 Fourier spectra of the TEM images Figure 5 a (a) and Figure 6 b (b). It is well known that the local atomic structure can be modified by an electron beam and is visible in TEM as radiation damage, nanoparticle coagulation, or other changes [18–21]. The density of such areas and the level of structure damage depend on the current density and the incident beam energy. In our investigations, the current density did not exceed 10 to 20 A/cm2 at beam energy of 80 to 300 kV. This allowed us to choose the conditions under which local

structure modification was negligible and not visible under electron beam irradiation. One method proposed for estimating diffusion coefficients of amorphous alloys is by direct measurement of the find more crystals’ size changes under heat using the electron microscope [22]. We estimated the diffusion coefficient by direct observation of atoms moving in the specimens by using TEM with high-pass diffusion [23] at the beginning of structure relaxation and at crystallization at elevated temperatures. The

most visible changes in the alloy structure Vitamin B12 occurred at the vacuum-crystal interface. In these areas, the local diffusion coefficient was much higher, up to 10−18 cm2/s. This does not contradict prior findings that the mean value of the diffusion coefficient ranges from 10−25 to 10−24 cm2/s for Co/Ni in W and W in Co/Ni [24, 25] at 200°C. Our primary goal was to estimate the diffusion coefficient through direct local observation of the beginning of atomic structure relaxation and crystallization at low-temperature annealing. Investigations of local chemical composition using EELS and EDS showed an inhomogeneous distribution of elements in the NiW alloy. Figure 9 shows the high-angle annular dark-field scanning transmission electron microscopy (HAADF STEM) image of an area with points for analysis. Lighter areas correspond to thicker regions and/or higher average atomic numbers, while the darker areas correspond to thinner regions and/or lower average atomic numbers. Table 1 shows the results of the processed EDS spectra where the W content was higher in thinner areas.