Abstract: A method for automatically aligning a scanning tunneling electron microscope (STEM) for acquiring precession electron diffraction (PED) mapping data includes the generation of an incident electron beam aligned with a STEM optic axis and focused on a sample region. A non-inclined signal is acquired of the spatial distribution from the sample region, by scanning the aligned incident beam across multiple discrete locations and acquiring a signal associated with each location. The method can further include the inclination of the incident electron beam to a fixed inclination angle relative to the optic axis and then acquiring an inclined signal spatial distribution from the sample region by scanning the inclined incident beam across the multiple discrete locations while applying a cyclic azimuthal scanning protocol to the inclined beam and acquiring a signal associated with each location.

Abstract: A scanning transmission electron microscope is adapted to acquire high quality precession electron diffraction (PED) patterns by means of separated scanning deflectors and precession deflectors. Magnetic or electrostatic deflectors may be used for scanning and for precession. This enables independent optimization of parameters for each deflection system to achieve a broad operating range simultaneously for both deflection systems.

Abstract: A method for automatically aligning a scanning tunneling electron microscope (STEM) for acquiring precession electron diffraction (PED) mapping data includes the generation of an incident electron beam aligned with a STEM optic axis and focused on a sample region. A non-inclined signal is acquired of the spatial distribution from the sample region, by scanning the aligned incident beam across multiple discrete locations and acquiring a signal associated with each location. The method can further include the inclination of the incident electron beam to a fixed inclination angle relative to the optic axis and then acquiring an inclined signal spatial distribution from the sample region by scanning the inclined incident beam across the multiple discrete locations while applying a cyclic azimuthal scanning protocol to the inclined beam and acquiring a signal associated with each location.

Abstract: A scanning transmission electron microscope is adapted to acquire high quality precession electron diffraction (PED) patterns by means of separated scanning deflectors and precession deflectors. Magnetic or electrostatic deflectors may be used for scanning and for precession. This enables independent optimization of parameters for each deflection system to achieve a broad operating range simultaneously for both deflection systems.

Abstract: A method and system are disclosed for improving characteristic peak signals in electron energy loss spectroscopy (EELS) and energy dispersive x-ray spectroscopy (EDS) measurements of crystalline materials. A beam scanning protocol is applied which varies the inclination, azimuthal angle, or a combination thereof of the incident beam while spectroscopic data is acquired. The method and system may be applied to compositional mapping.

Abstract: A process for measuring strain is provided that includes placing a sample of a material into a TEM as a sample. The TEM is energized to create a small electron beam with an incident angle to the sample. Electrical signals are generated that control multiple beam deflection coils and image deflection coils of the TEM. The beam deflection control signals cause the angle of the incident beam to change in a cyclic time-dependent manner. A first diffraction pattern from the sample material that shows dynamical diffraction effects is observed and then one or more of the beam deflection coil control signals are adjusted to reduce the dynamical diffraction effects. One or more of the image deflection coil control signals are then adjusted to remove any motion of the diffraction pattern.

Abstract: A process for measuring strain is provided that includes placing a sample of a material into a TEM as a sample. The TEM is energized to create a small electron beam with an incident angle to the sample. Electrical signals are generated that control multiple beam deflection coils and image deflection coils of the TEM. The beam deflection control signals cause the angle of the incident beam to change in a cyclic time-dependent manner. A first diffraction pattern from the sample material that shows dynamical diffraction effects is observed and then one or more of the beam deflection coil control signals are adjusted to reduce the dynamical diffraction effects. One or more of the image deflection coil control signals are then adjusted to remove any motion of the diffraction pattern.

Abstract: A method and system are disclosed for improving characteristic peak signals in electron energy loss spectroscopy (EELS) and energy dispersive x-ray spectroscopy (EDS) measurements of crystalline materials. A beam scanning protocol is applied which varies the inclination, azimuthal angle, or a combination thereof of the incident beam while spectroscopic data is acquired. The method and system may be applied to compositional mapping.