Physical Methods for Characterizing Solids

FIGURE 2.1 (a) Section through an X-ray tube (h) an X-ray emission spectrum. 

FIGURE 2.2 X-ray diffraction by a crystal of beryl using tbe Laue method. 

FIGURE 2.3 Bragg reflection from a set of crystal planes with a spacing dhki- 

This must be equal to an integral number, n, of wavelengths. If the wavelength of the X-rays is A, then nX=2dhi mehu 

When n=, the reflections are called first order, and when n=2 the reflections are second order and so on. However, the Bragg equation for a second order reflection from a set of planes hkl is 2k=2 di, 

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