This standard is directly traceable to the crystal lattice constant of silicon and performs all major
instrument calibrations for Transmission Electron Microscopy:
- All TEM magnification ranges
- Camera constant
- Image/diffraction pattern rotation
MAG*I*CAL consists of an electron transparent cross-sectional TEM sample made from a MBE grown, single-crystal
semiconductor wafer. When the calibration structure is viewed in a TEM, it appears as a series of light and dark
layers where the layer thicknesses are accurately known.
The calibration thickness measurements of the light (silicon) and dark (SiGe alloy) layers are based
on careful TEM measurements of the <1 1 1> lattice spacing of silicon, which is visible on the
calibration sample itself and are supported by X-ray diffraction measurements.
The layer spacings are designed so the sample can be used to calibrate the entire magnification range
in TEM from 1,000X to 1,000,000X. As the sample is also a single crystal of silicon, the calibrations
requiring electron diffraction information, such as the camera constant and image/diffraction pattern
rotation, can also be performed easily and unambiguously.
The MAG*I*CAL calibration sample is directly traceable to the lattice constant of silicon <1 1 1> (0.3135428nm). This constant can be measured directly on the MAGICAL sample, providing unbroken traceability to a fundamental constant of nature. One single calibration sample can be used to provide all three of the major TEM instrument calibrations at all magnifications and all cameras lengths.
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