13th International Conference on Fracture June 16–21, 2013, Beijing, China -2- After the heating process, morphologies of the oxidized specimens were characterized by the scanning electron microscopy (SEM, JSM-7000FK), Energy-dispersive X-ray (EDX) and X-ray diffraction (XRD). 3. Results and discussion 3.1. Experiment results As shown in Fig. 1 grass like architectures, which were 8-70 μm in size with 1-2.5 μm width leaves grew mainly at the edge of the catalyst island. The contrast experiments showed that without the nickel based catalyst there would be no grass like architectures growing on the Si substrate even after the same heating process. Meanwhile, there was no grass like architectures growing on Si substrates which were heated at thermostatic drier and vacuum tank. Therefore, the catalyst, humidity and oxygen atmosphere were considered to be three of the important factors to affect the growth of grass like architectures. Figure 1. SEM image of grass like architectures Element Weight% Atomic% O K 12.17 35.50 Cu K 87.83 64.50 Totals 100 Figure 2. EDX spectra of grass like architectures on Si substrate Figure 3. XRD spectra of grass like architectures on Si substrate Energy-dispersive X-ray (EDX) analysis (Fig.2) indicates that the architectures are composed of Cu elements (35.50%) and oxygen elements (64.50%). The architecture was composed of Cu2O
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