It is worth noting that there are also some amorphous areas present in Figure 2d. Actually, these regions are not composed of real amorphous phase. When we slightly tilted the specimen, the regions that appeared to be amorphous could change into crystallized structure, which suggested that there existed the misorientation difference between different regions and that the ‘amorphous’ regions are not really composed of amorphous phase, but crystallized phase. Therefore, it is reasonably believed that there exists the same ‘crystallized effect’ of nanomultilayered films in nanocomposite films, namely,
when Si content increases to an appropriate value, that is, SiN x interfacial phase reaches to a proper thickness, the SiN x interfacial phase can be crystallized under the template effect of adjacent TiN crystallites, which can coordinate Torin 2 price the misorientations between TiN crystallites and grow coherently with them. In high magnification of TiAlN/SiN x film, it can also be observed that the lattice fringes continuously go across adjacent TiAlN crystallites through SiN x interfaces, suggesting that SiN x phase has been crystallized between adjacent TiAlN crystallites and grows coherently with them (Figure 2e). Comparatively, the SiN x interfacial thickness of TiAlN/SiN x film is smaller (about 0.3 to 0.5 nm) based on Figure 2e than that (about 0.5 to 0.7 nm) of TiN/SiN x film in Figure 2d, which is agreement
with the fact Pifithrin�� that the Si/Ti0.7Al0.3 ratio of 3:22 in TiAlN/SiN x film is lower than Si/Ti ratio of 4:21 in TiN/SiN x film. Figure 3 shows that the typical cross-sectional HRTEM images of TiN/SiN x nanocomposite film with Si/Ti ratio of 5:20. It can be seen from Figure 3a that the thickness of SiN x interfacial phase increases compared with Figure 2b 3-mercaptopyruvate sulfurtransferase (Si/Ti = 4:21). The average size of TiN crystallite is about 4 to 8 nm, smaller than that in Figure 2b (6 to 10 nm). From the high-magnification image in Figure 3b,
it can be seen that SiN x interfacial phase presents amorphous state, rather than crystallized state, suggesting that SiN x interfacial phase cannot maintain the crystallization with high interfacial phase thickness and transforms back into amorphous state. Amorphous SiN x interfacial phase breaks the epitaxial growth structure between the adjacent TiN nanocrystallites, leading to the various growth misorientations for TiN nanocrystallites, as shown in Figure 3b. Figure 3 Cross-sectional HRTEM images of TiN/SiN x nanocomposite film with high Si content (Si/Ti = 5:20). (a) Low magnification and (b) high magnification. According to the above analysis, TiN/SiN x and TiAlN/SiN x nanocomposite films have the same interfacial morphological evolution with nanomultilayered films. If this is a fact, the TiN/SiNx and TiAlN/SiNx nanocomposite films should be effectively strengthened when SiN x interfacial phase is well crystallized and the film presents the highest crystallization degree.