Molybdenum radiation

The cubic space group Pm3m (no systematic absences) was chosen for X-ray diffraction studies for reasons previously cited (9). Preliminary crystallographic experiments and subsequent data collection were performed at 2A°C with an automated, four-circle Syntex PI diffractometer, equipped with a graphite monochromator and a pulse-height analyzer. Molybdenum radiation was used for all experiments (Ka, X 0.70930 a K 2 ... 

Figure 9. Niobium-filtered molybdenum radiation x-ray patterns of I2-KI complexed nylon 66 (A) fiber axis vertical, x-ray beam perpendicular to (100) planes (B) fiber axis vertical, x-ray beam perpendicular to (010) planes, and (C) x-ray beam parallel to the fiber axis...

FIGURE 5.17 Cellulose diffraction patterns. Top left synchrotron radiation x-ray diffraction pattern for cotton fiber bundle. The fiber was vertical and the white circle and line correspond to a shadow from the main beam catcher and its support. (Credit to Zakhia Ford.) Top right electron diffraction pattern of fragments of cotton secondary wall. The much shorter arcs in the top right figure are due to the good alignment and small number of crystallites in the electron beam. (Credit to Richard J. Schmidt.) Bottom a synthesized powder pattern for cellulose, based on the unit cell dimensions and crystalline coordinates of Nishiyama et al. [209]. (Credit to Zakhia Ford.) Also shown are the hkl values for the Miller indices. The 2-theta values are for molybdenum radiation instead of the more commonly used copper radiation. 

Here m is a coelScient that parameterizes a detector-wavelength combination. For example, a CCD detector optimized for copper radiation used m = 0.1763. One optimized for molybdenum radiation had m = 0.3274. No derivation of this formulation has to date been published. 

A Syntex four-circle computer-controlled diffractometer with a graphite monochromator and a pulse-height analyzer was used for preliminary experiments and for the subsequent collection of diffraction intensities. Molybdenum radiation (Ka, X = 0.70930 A ... 

Figure 2.7 taken from Compton and Allison [1] shows the Compton wavelength shift as a function of the scattering angle when molybdenum radiation is scattered... 

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