42
Substitution of values for h, k, and 1 yields the series
of values for F in Table 2.2
The DO22 reciprocal lattice constructed using those
values of F listed in Table 2.2 is shown in Figure 2.13a.
The lattice is constructed using DO22 coordinates and
compared to a corresponding FCC construction in the two
dimensional B = [100] and B = [001] sections shown in
Figure 2.13b. Note that both the (020) and (200) of the
DO22 correspond to the (020) and the (200) of the parent
FCC lattice since a/2 FCC = a/2D022* Also, the (004) DO22
= l/4(2a) (the "A" indices from Table 2.2) = a/2 FCC. The
fundamental reflections of the DO22 are then in the same
reciprocal lattice positions as the fundamental FCC
reflections. The (Oil), (022), etc. of the DO22 are 1/4
multiples of the FCC (042). This makes the Mo rich (Oil)
planes of the DO22 structure the (042) Mo rich planes of
the FCC parent lattice.
2.3.2 Dla/Pt2Mo/Ll2 Reciprocal Lattices
Similar constructions result in the reciprocal
lattices of N4M0 and N2M0, shown respectively in Figures
2.14 and 2.15, both lattices in FCC coordinates. The
reciprocal lattice of the FCC ordered gamma prime is shown
in Figure 2.16.