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Detection of superlattice lines

We have already seen that the intensity of a superlattice line from an ordered solid solution is much lower than that of a fundamental line. Will it ever be so low that the line cannot be detected We can make an approximate estimate by ignoring the variation in multiplicity factor and Lorentz-polarization factor from line to line, and assuming that the relative integrated intensities of a superlattice and fundamental line are given by their relative F values. For fully ordered AuCus, for example, we find from Eqs. (13-1) that [Pg.391]

Superlattice lines are therefore only about one-tenth as strong as fundamental lines, but they can still be detected without any difficulty, as shown by Fig. 13-3. [Pg.392]

But in CuZn, even when fully ordered, the situation is much worse. The atomic numbers of copper and zinc are 29 and 30, respectively, and, making the same assumptions as before, we find that [Pg.392]

This ratio is so low that the superlattice lines of ordered CuZn can be detected by x-ray diffraction only under very special circumstances. (The powder pattern of this alloy, ordered or disordered, ordinarily appears to be that of a body-centered cubic substance.) The same is true of any superlattice of elements A and B which differ in atomic number by only one or two units, because the superlattice-line intensity is generally proportional to (/a — /b).  [Pg.392]

The two points on the curve show the corrections for the scattering of Zn Ka radiation by copper and zinc atoms. [Pg.393]


See other pages where Detection of superlattice lines is mentioned: [Pg.391]    [Pg.391]    [Pg.393]   


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