The defect structures in orthorhombic C54 crystallites in thin films of Mo-doped TiSi2 produced by co-sputtering were investigated by transmission electron microscopy. Almost all C54 crystallites contain a twin boundary parallel to (101), dividing a crystallite into two regions, each of which also contains many thin twins with the habit plane parallel to (001), which was inclined by about 45° from (101). Both of the regions divided by the twin boundary parallel to (101) tended to have facets on (001) as well as thin twins with the habit plane parallel to (001). As a result, C54 crystallites exhibited a characteristic oak-leaf shape. While twins with the (001) habit plane were observed in

C54 crystallites in both binary and Mo-doped TiSi2 thin films, those with the (101) habit plane were present only in Mo-doped TiSi2 thin films. The origin of (101) twins in Mo-doped TiSi2 was explained in terms of a change in the c/a axial ratio upon alloying TiSi2 with Mo.

{101} Twins in Mo-Doped TiSi2 Thin Films with the C54 Structure. H.Inui, N.L.Okamoto, T.Hashimoto, K.Tanaka, M.Yamaguchi: Philosophical Magazine, 2003, 83[12], 1463-78