Pole figure crystallography
How do you analyze a pole figure?
To determine the pole figure for an (hkl) reflection, the Schulz goniometer is generally used (Figure 10.13(a)).
The specimen is set at the appropriate Bragg angle θ and the plane of the specimen can be varied by angles α and ϕ..
How do you plot pole figures?
By default MTEX plots pole figures by drawing a circle at every measurement position of a pole figure and coloring it corresponding to the measured intensity.
MTEX tries to guess the right size of the circle in order to produce a pleasing result..
How is pole figure measured?
A pole figure measurement is a technique where the diffraction angle is fixed and the diffracted intensity is recorded by varying two geometrical parameters, such as the α angle (tilt angle of the diffraction vector from the surface normal direction of a sample) and the β angle (ϕ rotation angle of the diffraction .
What is a pole figure crystallography?
A pole figure is a graphical representation of the orientation of objects in space.
For example, pole figures in the form of stereographic projections are used to represent the orientation distribution of crystallographic lattice planes in crystallography and texture analysis in materials science..
What is pole figure in ebsd?
A Pole figure is a 'Stereographic Projection' in which orientations are plotted as two dimensional projections.
In a Pole figure, the poles, i.e. the normal to a lattice plane for a chosen family of planes, are plotted relevant to the sample reference axes..
- A Crystal projection is a quantitative method of representing a three dimensional crystal on a two dimensional planar surface.
Different projections are used for different purposes but each has its own set of rules so that the projection bears a known and reproducible relationship to the crystal. - By default MTEX plots pole figures by drawing a circle at every measurement position of a pole figure and coloring it corresponding to the measured intensity.
MTEX tries to guess the right size of the circle in order to produce a pleasing result. - For pole figures the plane of interest is selected, whereas in inverse pole figures the sample direction of interest is selected.
It is a bit more intuitive to think of an inverse pole figure as showing which plane normal in the crystal is parallel to the selected sample direction.
A pole figure is a graphical representation of the orientation of objects in space. For example, pole figures in the form of stereographic projections are used to represent the orientation distribution of crystallographic lattice planes in crystallography and texture analysis in materials science.
To draw a pole figure, one chooses a particular crystal direction (e.g. the normal to the (100) plane) and then plots that direction, called a pole, for every crystal relative to a set of directions in the material.
Definition
Consider an object with a basis attached to it
Stereographic projection
The upper sphere is projected on a plane using the stereographic projection. Consider the (x
Geometry in the pole figure
A Wulff net is used to read a pole figure. The stereographic projection of a trace is an arc
Application
The structure of a crystal is often represented by the pole figure of its crystallographic planes
External links
• Wulff net with a step of 2° ( PDF file, 1p, 272KB)• http://www.texture
Can a single crystal be plotted on a pole figure?
A single crystal can be plotted on the pole figure and there is no ambiguity regarding its orientation
However, as more crystallite poles are plotted onto the pole figure, the specific orientation of a particular crystallite can no longer be defined
What is a pole figure for a polycrystalline sample?
Concept of a pole-figure for a polycrystalline sample is fairly simple
A polycrystalline sample with preferred orientation is placed at the center of a sphere so that the MD lies in the equatorial plane of the sphere
Normals to one set of planes are projected on to the surface of the sphere, just as they are in the Wulff net projection
What is a pole figure?
A pole figure maps the directions of a set of symmetrically equivalent "poles," that is, normal directions of lattice planes, onto the - plane of a Cartesian - - coordinate system
A pole figure is simply a stereogram with its axes defined by an external frame of reference with particular hkl poles plotted onto it from all of the crystallites in the polycrystal. Typically, the external frame is defined by the normal direction, the rolling direction, and the transverse direction in a sheet (ND, RD and TD respectively.
Way of visually representing the orientation of objects in 3D space
A pole figure is a graphical representation of the orientation of objects in space.
For example, pole figures in the form of stereographic projections are used to represent the orientation distribution of crystallographic lattice planes in crystallography and texture analysis in materials science.
