Reproducible Textures

The orientation distribution function of a textured polycrystalline material may be split into aneven and odd part; the latter is not reproducible from pole figure measurements as has beenrecently shown. The class of textures containing only a reproducible part is considered. In thecase of axially symmetric textures (fibre textures), these take on a very simple form. They are,however, not the only type of reproducible textures as has been assumed. A sample having areproducible texture is centrosymmetric, even in the most general case of non-centrosymmetric,enantiomorphic crystals of one crystal form only. Symmetry elements of this kind have beencalled non-conventional ones. They may be described by black-and-white or Shubnikov groups.Reproducible textures correspond to a non-conventional centre of inversion as an element ofsample symmetry and vice versa.