Calculation of the effect of twinning on (101) on the effective particle sizes determined from X-ray line profiles for the L1₀ superlattice

The Fourier coefficients of the X-ray diffraction line profiles from an ordered face-centred tetragonal (L1₀) structure such as MgIn or CuAu have been calculated assuming the presence of twin and incoherent boundaries on (101). It is found that reflection components with (h-l) = 0 are not affected by twinning on (101). The theoretical expression for the effective particle size is compared with some measured particle sizes for cold-worked MgIn.