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 Selleck 3MA (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 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 Linsitinib price 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 Farnesyltransferase 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.