On the texture in diffusion-grown layers of silicides and germanides with the FeB structure, MeX (Me=Ti, Zr; X=Si, Ge) or the ZrSi₂ structure (ZrSi₂, HfSi₂, ZrGe₂)

In diffusion-grown layers of compounds with the orthorhombic FeB- and ZrSi₂-type structures a pronounced texture is present which is rotationally symmetric with respect to the direction of diffusion. In FeB-type structures a [101]-fibre texture is observed for ZrSi and HfSi and a [100]-fan texture for TiSi and ZrGe. In ZrSi₂-type compounds the b axis is always perpendicular to the direction of diffusion; different compounds, however, show different textures: a [010]-fan texture for ZrSi₂, a [100]-fibre texture for HfSi₂ and a <101>-fibre texture for ZrGe₂. The textures are explained in terms of preferential diffusion along specific crystallographic directions which can be derived from the crystal structures. At high temperatures a second texture component has been observed in HfSi layers and in layers with the ZrSi₂ structure. This second component can be considered as a recrystallization texture and can be derived from the original texture by a rotation of the crystallites of 20-25° around a simple crystallographic direction. The existence of a so-called TiGe phase with the FeB structure in the temperature region 1070-1270 K is questionable. Only Ti₆Ge₅ has been produced and this compound showed a [001]-fibre texture.