SYSTEMS AND METHODS FOR FRAME CONTROL IN TEXTURE ANALYSIS
A system may obtain a plurality of experimental diffraction patterns. A system may identify a crystallographic orientation of each diffraction pattern of the plurality of experimental diffraction patterns. A system may build one or more pole figures. A system may select a reference spherical function having a reference frame. A system may correlate spherical images from the pole figures and the reference spherical function. A system may determine a sample frame of the crystallographic orientations. A system may rotate the crystallographic orientations of the plurality of experimental diffraction patterns into alignment with the reference frame to produce a plurality of rotated crystallographic orientations.
1 . A method for characterizing a material, the method comprising:
obtaining a plurality of experimental diffraction patterns;
identifying a crystallographic orientation of each diffraction pattern of the plurality of experimental diffraction patterns;
building one or more pole figures;
selecting a reference spherical function having a reference frame;
correlating spherical images from the pole figures and the reference spherical function;
determining a sample frame of the crystallographic orientations; and
rotating the crystallographic orientations of the plurality of experimental diffraction patterns into alignment with the reference frame to produce a plurality of rotated crystallographic orientations.
2 . The method of claim 1 , wherein obtaining the plurality of experimental diffraction patterns includes detecting backscattered electrons from a sample in a scanning electron microscope.
3 . The method of claim 1 , wherein obtaining the plurality of experimental diffraction patterns includes detecting diffracted electrons from a sample in an transmission electron microscope.
4 . The method of claim 1 , further comprising determining a rotated texture intensity of the plurality of rotated crystallographic orientations.
5 . The method of claim 1 , wherein rotating the crystallographic orientations includes determining an angular difference between the reference spherical function and the plurality of rotated crystallographic orientations via spherical harmonic indexing.
6 . The method of claim 1 , further comprising binning the crystallographic orientations prior to determining the correlating the spherical images.
7 . The method of claim 6 , wherein the crystallographic orientations are binned in an equal area grid.
8 . The method of claim 7 , wherein the equal area grid is a square Lambert binning grid.
9 . The method of claim 1 , wherein determining a sample frame includes comparing a texture measurement of the pole figures to a reference texture of the reference spherical function.
10 . The method of claim 1 , wherein rotating the crystallographic orientations of the plurality of experimental diffraction patterns into alignment with the reference frame includes determining a rotational axis direction and a rotational angle.
11 . A method of characterizing a material, the method comprising:
obtaining a plurality of experimental diffraction patterns;
identifying a crystallographic orientation of each diffraction pattern of the plurality of experimental diffraction patterns;
building one or more pole figures;
determining symmetry group of the plurality of experimental diffraction patterns;
selecting a reference spherical function having a reference frame based at least partially on the symmetry group;
correlating spherical images from the pole figures and the reference spherical function;
determining a sample frame of the crystallographic orientations relative to the reference frame; and
rotating the crystallographic orientations of the plurality of experimental diffraction patterns into alignment with the reference frame to produce a plurality of rotated crystallographic orientations.
12 . The method of claim 11 , further comprising determining a symmetry descriptor for each primary direction of the experimental diffraction patterns.
13 . The method of claim 12 , further comprising creating a composite symmetry descriptor with a weighted sum of the symmetry descriptor for each primary direction of a crystal structure of the material.
14 . The method of claim 12 , further comprising calculating a target symmetry descriptor in accordance with a known symmetry group.
15 . The method of claim 11 , further comprising enforcing symmetry on the crystallographic orientations.
16 . The method of claim 11 , wherein symmetry is enforced after smoothing a dataset of the crystallographic orientations.
17 . The method of claim 16 , wherein the symmetry is an orthorhombic symmetry based at least partially on a processing of the sample.
18 . A system for characterizing a material, the system comprising:
an electron microscope including an electron source configured to produce electrons;
a detector configured to receive diffracted electrons produced by the electron source; and
a computing system in data communication with the detector, the computing system including:
a processor, and
memory having instructions stored thereon that, when executed by the processor, cause the computing system to:
obtain a plurality of experimental diffraction patterns,
identify a crystallographic orientation of each diffraction pattern of the plurality of experimental diffraction patterns,
build one or more pole figures;
select a reference spherical function having a reference frame;
correlate spherical images from the pole figures and the reference spherical function;
determine a sample frame of the crystallographic orientations, and
rotate the crystallographic orientations of the plurality of experimental diffraction patterns into alignment with the reference frame to produce a plurality of rotated crystallographic orientations.
19 . The system of claim 18 , wherein the electron microscope is a scanning electron microscope.
20 . The system of claim 18 , wherein the electron microscope is a transmission electron microscope.