Evidence of non-cubic lattice distortions around vacant sites in Co–Ga β' phases

Diffuse X-ray diffraction from Co-Ga single crystals containing 48 to 56 at.% Co gives evidence for strong distortion fields around vacant sites in the Co sublattice and less strong fields around Co atoms on the Ga sublattice. The distortion is comparable to that occurring in Zr-20 wt.% Nb alloys and is characterized by shifts of atoms parallel to (111). The distortion has some similarity to the atomic structure of the ω phase found in Zr-10 wt % Nb.