2

2. Below in Figure 3 is the XRD pattern obtained from a sample of Pt-Cu alloy nanoparticles. The XRD patterns of pure Pt and Cu were in the appendix. 1) Index the peaks of the XRD pattern 2) Calculate the average lattice constant with standard deviation of the unit cell of the sample. 3) Calculate the composition of Pt and Cu of the sample 4) Estimate the size of the nanoparticles in the sample 1000 - 800- 40.0 600 Counts 46.6 400 67.8 200 - 819 0+ 30 40 50 70 80 90 20 (degree) Figure 3. XRD pattern of a sample of Pt-Cu alloy nanoparticles