Chemistry Reference
In-Depth Information
FIGURE 8.3
(a) Definition of pole direction angles a and b. (b) Stereographic projection in
pole figure.
some literature, the angle between the sample normal and the pole direction (x)is
used in the radial direction. The pole density at the point P projects to the point P
0
on
the equatorial plane through a straight line from P to the point S. The pole densities
at all directions are mapped onto the equatorial plane by stereographic projection.
As shown in Figure 8.3(b), this two-dimensional pole density mapping on the
equatorial plane is called a pole figure. The azimuthal angle b projects to the pole
figure as a rotation angle about the center of the pole figure from the sample direction
S
1
. The radial angle a is projected to the pole figure with a nonlinear scale. If the
