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. A diffraction pattern is then collected from a strained area of the material after the adjusting step, and the strain is then determined from a numerical analysis of the strained diffraction pattern compared to a reference diffraction pattern from an unstained area of the material.
H01J 37/26 - Electron or ion microscopesElectron- or ion-diffraction tubes
G01N 23/225 - Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups , or by measuring secondary emission from the material using electron or ion microprobes
G01N 23/20 - Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups , or by using diffraction of the radiation by the materials, e.g. for investigating crystal structureInvestigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups , or by using scattering of the radiation by the materials, e.g. for investigating non-crystalline materialsInvestigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups , or by using reflection of the radiation by the materials
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.
G01N 23/225 - Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups , or by measuring secondary emission from the material using electron or ion microprobes
H01J 49/44 - Energy spectrometers, e.g. alpha-, beta-spectrometers
H01J 37/28 - Electron or ion microscopesElectron- or ion-diffraction tubes with scanning beams
3.
SYSTEM AND PROCESS FOR MEASURING STRAIN IN MATERIALS AT HIGH SPATIAL RESOLUTION
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. A diffraction pattern is then collected from a strained area of the material after the adjusting step, and the strain is then determined from a numerical analysis of the strained diffraction pattern compared to a reference diffraction pattern from an unstrained area of the material.
G01N 23/225 - Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups , or by measuring secondary emission from the material using electron or ion microprobes
patents
