请使用高级语法及词汇润色以下句子：Figure 1a shows the X-ray diffraction patterns of pure Cu Cu-coated graphite and mixed powders with Cr2AlC The results indicate that there are no other impurities in the raw materials

In Figure 1(a), the X-ray diffraction patterns of pure Cu, Cu-coated graphite, and mixed powders with Cr2AlC are illustrated. The findings suggest that the raw materials utilized in the composite material preparation are devoid of any other impurities and that no novel phases are formed during the mixing procedure. The phase of the mixed powder is composed of graphite, copper, and Cr2AlC.