Specific Process Knowledge/Characterization/XRD: Difference between revisions
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===Pole figure=== | ===Pole figure=== | ||
Pole figures can be used to determine the orientation of a crystal. For polycrystalline materials, it is possible to determine if there is a preferred direction of the crystal grains. In a pole figure, a measurement of a predefined peek for the material is measured in the half sphere above the sample. This will result in a map of intensities in relation to the angles from the surface normal and along sample rotation. For instance if you have a single crystalline sample with a [0 0 1] surface and measure on the [1 1 1] lattice plane, you should find 4 peaks spaced 90° in beta and at 35.26° in alpha. | Pole figures can be used to determine the orientation of a crystal. For polycrystalline materials, it is possible to determine if there is a preferred direction of the crystal grains. In a pole figure, a measurement of a predefined peek for the material is measured in the half sphere above the sample. This will result in a map of intensities in relation to the angles from the surface normal and along sample rotation. For instance if you have a single crystalline sample with a [0 0 1] surface and measure on the [1 1 1] lattice plane, you should find 4 peaks spaced 90° in beta and at 35.26° in alpha. | ||
Peak angles can be calculated by simple vector calculations; however, I have made a [[small MATLAB script]] calculating them for you. To use the script open MATLAB and call the program with two vectors as input. First vector should be your surface orientation, second input the plane you measure on. For a [1 1 1] substrate surface and a [3 1 1] plane and a [0 0 1] substrate surface and a [1 3 3] plane, where the measurement planes are dependent on the 2theta angle, the command looks like this: | Peak angles can be calculated by simple vector calculations; however, I have made a [[small MATLAB script]] calculating them for you. To use the script open MATLAB and call the program with two vectors as input. First vector should be your surface orientation, second input the plane you measure on. For a [1 1 1] substrate surface and a [3 1 1] plane and a [0 0 1] substrate surface and a [1 3 3] plane, where the measurement planes are dependent on the 2theta angle, the command looks like this: | ||
PoleFigureAngles([1 1 1; 0 0 1],[3 1 1; 1 3 3]) | PoleFigureAngles([1 1 1; 0 0 1],[3 1 1; 1 3 3]) | ||
It is also possible to give a path for a file exported from 3D Explore with contour data from a measurement, and a rotational correction for the data: | |||
PoleFigureAngles([1 1 1; 0 0 1],[3 1 1; 1 3 3],'\Au_thin_inplanepole_WF1_m2.txt',30.9) | |||
Which will give the following table and pictures, without a file input only the table and the first graph will be given: | |||
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[[File:PoleFigureAngles.png|400px]][[File:Overlay.png|400px]] | [[File:PoleFigureAngles.png|400px]][[File:Overlay.png|400px]] | ||
Rigaku describes Pole figures [[:File:X-ray thin film measurements techniques VII Pole figure measurement.pdf|this paper]]. | Rigaku describes Pole figures [[:File:X-ray thin film measurements techniques VII Pole figure measurement.pdf|this paper]]. | ||