at the cuboid edge.) This is shown clearly in Figure 5.9

and in a lattice image, section 5.1.4.2. Note the

concentrations of the Dla phase at the corners of the

gamma prime cuboids in Figures 5.6c and 5.6e.

 The Pt2Mo phase is also present in the alloy. It can

be present as discreet Ni2Mo precipitates, or it can be

present layered with the D022 and Dla, as it appears to be

in Figure 5.6d.

 In order to describe the actual three dimensional

arrangement of these NixMo phases, it is necessary to look

along the third 100 direction in the crystal. This can be

done by tilting from B = [001] to a B = [112] direction, a

tilt of 35.3 degrees. When tilted to this orientation,

multiples of the (042) and (402) reflections can be used

to image the D022 and Dla precipitates (Figure 5.8).

Imaging with a 1/4 multiple of either of these reflections

will yield an image of the D022 phase on the previously

unimageable 001 face of the gamma prime. Using the 1/5

multiples will image two additional Dla variants.

 Figure 5.10 shows the three faces of the gamma prime

cube with the four possible D022 planes on each face. The

1/4 (402) and the 1/4 (042) variants are on the same 001

face. Since they are from the same D022 variant, imaging

with either of them will give the same image.

 The 1/5 (042) variant will appear on two faces of the

gamma prime. First, it will appear on the (001) face. It