Diffuse scattering shows

Fig. 11a and b. Oscillation patterns recorded from a 6-phosphogluconate dehydrogenase and b rabbit serum transferrin showing rich and highly oriented molecular diffuse scattering features... 

This technique measures the optical spectrum of light which is diffusely scattered off the catalyst sample. Absorption frequencies are characteristic of certain arrangements of molecules and their environment. Even pure compounds give rather broad diffuse spectra, and catalysts show even broader spectra. Hence, results are only semiquantitative at best. In regards to molybdena catalysts, the information derived with this technique is the coordination environments of Mo and Co in the catalyst. 

Figure 15.3. Simplified diagram showing nearly normal incidence of a beam of light (L,) from an optical medium with refractive index ni through a thin solid film of thickness d with refractive index n2 (L, and L/ regular reflections from interfaces P, and P2. L-, diffuse scattered reflections from the transmitted light).

Figure 8.36. DF image formed with diffusely scattered electrons showing a band about 10 nm wide along a grain boundary between two olivine grains in a hot-pressed olivine-basalt aggregate annealed for 200 hours near 1250°C at 1 GPa. (From Vaughan and Kohlstedt 1982.)...

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