An electron microscopic phase analysis of rutile plus 0 to 25mol%CrO1.5 at 1573K was reported. A "rutile" matrix, containing mottled contrast, short crystallographic shear planes and an unusually high density of dislocations, co-existed with lamellae of (253)r crystallographic shear planes (approx MX1.97) for 0 to 8 mol%CrO1.5. For 8 to 25mol% at least 50 different structures were characterized. Within experimental error there was an essentially continuous variation of crystallographic shear plane orientation and spacing with composition. The crystallographic shear planes cooperatively reorient from (253)r to (121)r, pivoting about the [111]r zone axis. The crystallographic shear plane spacing simultaneously decreased from 2.4 to 1.3nm. Lattice images showed that both the spacing and orientation of the crystallographic shear planes were very uniform within each crystal flake, confirming an earlier suggestion of continuous ordered solid solution.

Phase Analysis Studies of Titanium-Chromium Oxides Derived from Rutile by Crystallographic Shear. Philp, D.K., Bursill, L.A.: Journal of Solid State Chemistry, 1974, 10[4], 357-70