Bragg’s angle

The broad peaks around 23°, 29°, and 34° (20) (0 is the Bragg s angle) from the smaller inset could be attributed to linking of Mo to the sulfonic acid. The FTIR spectra of anhydrous sodium molybdate and MSA are shown in Figure 3.5. The spectrum of MSA shows the characteristic bonds of anhydrous sodium molybdate and chlorosulfonic acid. The absorptions in 3459, 2110, 1635, 1129, 909, 771, 637, 616, and 451 cm in the catalyst spectrum reveal both bonds in anhydrous sodium molybdate and the -OSO3H group. 

STA was characterized by x-ray fluorescence (XRF), XRD, and FTIR spectra. Figure 3.7 shows the XRD patterns for STA, which shows the presence of a tungstic acid crystalline phase supported on amorphous silica as a broad peak around 22° (20) (9 is the Bragg s angle). The three peaks in the 23°-25° region of the XRD spectrum could be attributed to the presence and linking of WO3 to the silica gel (Karami et al., 2012a Santato et al, 2001). 

There are two types of experimental techniques for single crystal studies. This classification is made on the basis of the wavelength A and Bragg s angle 0 as ... 

Type (A). Bragg s angle 0 is known but the wavelength A which satisfies the Bragg condition is unknown. 

Type (B). Bragg s angle 9 as well as the wavelength A which satisfy the Bragg condition are known. 

Fig. 7.15. Diffraction cones originating from different planes for the same X-ray wavelength. Different Bragg s angle for different planes present in different grains...

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