Practical Electron Microscopy and Database

The variation in s causes intensity oscillation across the disk. For instance, the intensity of a diffracted beam, I_g(s), is the function of an effective deviation parameter, s_eff:

           ---------------------------- [1990a]

where ξ_g is the extinction distance for the diffraction g. s_eff is given by,
           ---------------------------- [1990b]

Figure 1990 shows the calculated intensity profile of I_g as a function of s and 2θ_B (the separation of the (000)- and (hkl)-disks). The profile in Figure 1990 (a) is also called rocking curve.