Orientation textures

Berrett J F, Molino F, Porte G, Diat O and Lindner P 1996 The shear-induced transition between oriented textures and layer-sliding-mediated flows in a micellar cubic crystal J. Phys. Condens Matters 9513-17... 

Since the to angle tracks the 29 value, we need specify only 2 9, tp and x in order to correctly label the intensities read by the detector. In orientation texture studies the diffracted intensity is mapped as a function of a and x for a fixed 29. This provides (under appropriate assumptions) a measure of the probability... 

Most interpretations of orientation texture data are based on the assumption that the specimen is a sphere. A spherical specimen shape is not easily achieved for the kinds of materials we are dealing with and departures from sphericity interfere with the calculation of orientation functions (8). We expect to address this problem by calculating empirical correction functions that can be applied to specimen shapes that closely simulate the ones we use. This problem must be attacked using numerical integration in 3 dimensions, which is a computer-intensive activity. 

Many compounds, including clay minerals, form needle- or plateshaped crystals. With finely dispersed minerals, the electron diffraction method can give a special kind of diffraction pattern, the texture pattern, which contains a two dimensional distribution of a regularly arranged set of 3D reflections [2], Specimens of fine-grained lamellar or fiber minerals, prepared by sedimentation from suspensions onto supporting surfaces or films, form textures in which the component microcrystals have a preferred orientation. Texture patterns of lamellar crystals tilted with respect to the electron beam are called oblique texture electron diffraction patterns [1]. 

Figure 7.15. Schematic representation of polycrystalline randomly oriented substrate (a) and substrate with preferred orientation (texture) (h).

It is also possible to produce single-crystal ingots as well as highly oriented textured polycrystalline materials (i.e., those in which the grains exhibit a preferred orientation) by directional solidification. With the Bridgman technique... 

A component or object in which grain orientations are completely random is said to have no texture. If the material exhibits some preferred orientation, it is said to have a texture. The texture can be weak, moderate, or strong, depending on the percentage of grains that have the preferred orientation. Texture is produced in most materials, either as an unintended by-product of the processing method or with the intention to exploit favorable properties in one orientation. In some cases, processing methods or routes are chosen explicitly to develop a preferred texture. 

Becker M, Scheel H, Christiansen C, Strunk HP (2007) Grain orientation, texture, and internal stress optically evaluated by micro-Raman spectroscopy. J Appl Phys 101 063531-1-06351-10... 

Figure 6.1 Different types of compact 3D metal deposits according to Fischer [6.8]. (a) Field-oriented isolation type (FI) of an Ag deposit (b) field-oriented texture type (FT). Cross section of Cu deposit from acid CUSO4 solution with addition of /5-naphthaquinoline (c) base-oriented reproduction type (BR). Cross section of Cu deposit (d) randomly-oriented dispersion type (RD). Cross section of Cu deposit from acid CuSO solution with addition of naphthaquinoline.

V.K. Pecharsky, L.G. Akselrud, and P.Y. Zavalij, Method for taking into account the influence of preferred orientation (texture) in a powdered sample by investigating the atomic structure of a substance, Kristallografiya 32, 874 (1987). Engl, transl. Sov. Phys. Crystallogr. 32,514(1987). 

B. R. Stoner, S. R. Sahaida, J. P. Bade, P. Southworth, and P. J. Ellis, Highly oriented, textured diamond films on silicon via bias-enhanced nucleation and textured growth, J. Mater. Res., 8(6) 1334-1340 (1993)... 

The preferential orientation (texture) could be destroyed by cutting off a surface layer. 

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