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Update Calibrations

skoupy_r
2024-03-15 17:24:53 +01:00
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Calibrations.md

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Scanning step size is given by magnification and number of scanning points giving together field of view. In reality, original calibration may not be perfectly accurate and own re-calibration may be needed. Scanning step calibration is based on known inter-atomic distance. In our case _SmB6_ in [110] orientation where _Sm_ to _Sm_ distance is 2.92 or 4.13 A respectively. Line of 23 _Sm_ atoms was imaged in 499 pixels, 1 pixel is 22 * 2.92 / 499 = 0.1287 A. Microscope field of view at 30e6 magnification is 7.154 nm here divided into 512 pixels (pixel 0.1397 A). Correction factor between real and nominal pixel size is then 0.1287/0.1397 = 0.9212 = 92.12 % Scanning step size is given by magnification and number of scanning points giving together field of view. In reality, original calibration may not be perfectly accurate and own re-calibration may be needed. Scanning step calibration is based on known inter-atomic distance. In our case _SmB6_ in [110] orientation where _Sm_ to _Sm_ distance is 2.92 or 4.13 A respectively. Line of 23 _Sm_ atoms was imaged in 499 pixels, 1 pixel is 22 * 2.92 / 499 = 0.1287 A. Microscope field of view at 30e6 magnification is 7.154 nm here divided into 512 pixels (pixel 0.1397 A). Correction factor between real and nominal pixel size is then 0.1287/0.1397 = 0.9212 = 92.12 %
![calib-step](uploads/311e011f544aa091991f8a591ce8f02e/calib-step.PNG) ![calib-step](uploads/311e011f544aa091991f8a591ce8f02e/calib-step.PNG)
Pixel size calibration on \ce{SmB6} sample. Known \ce{Sm} to \ce{Sm} distance (2.92 \AA) is recalculated into real pixel size. Line profile is computed as sum of 7 rows to suppress image noise. Pixel size calibration on _SmB6_ sample. Known _Sm_ to _Sm_ distance (2.92 A) is recalculated into real pixel size. Line profile is computed as sum of 7 rows to suppress image noise.