Electron Microscopy

  1. General Instrumentation of Electron Microscopes
    1. The Electron Column
      1. Structure and Function
        1. Column Design Principles
          1. Vacuum Isolation
            1. Mechanical Stability Requirements
            2. Alignment and Calibration
              1. Optical Axis Alignment
                1. Lens Calibration Procedures
                  1. Systematic Alignment Protocols
                2. Electron Sources
                  1. Thermionic Emitters
                    1. Tungsten Filament
                      1. Operating Principles
                        1. Thermionic Emission Theory
                          1. Work Function Considerations
                          2. Advantages and Limitations
                            1. Cost and Simplicity
                              1. Limited Brightness and Lifetime
                              2. Operating Conditions
                                1. Temperature Requirements
                                  1. Vacuum Considerations
                                2. Lanthanum Hexaboride
                                  1. Material Properties
                                    1. Performance Characteristics
                                      1. Higher Brightness
                                        1. Better Stability
                                        2. Operating Requirements
                                          1. Ultra-High Vacuum Needs
                                            1. Temperature Control
                                        3. Field Emission Guns
                                          1. Cold Field Emission Gun
                                            1. Emission Mechanism
                                              1. Quantum Tunneling
                                                1. Field Enhancement
                                                2. Stability and Brightness
                                                  1. Current Fluctuations
                                                    1. Brightness Advantages
                                                    2. Vacuum Requirements
                                                      1. Ultra-High Vacuum Necessity
                                                        1. Contamination Sensitivity
                                                      2. Schottky Emitter
                                                        1. Thermal-Assisted Field Emission
                                                          1. Combined Thermal and Field Effects
                                                            1. Zirconium Oxide Coating
                                                            2. Performance Characteristics
                                                              1. Stability vs Cold FEG
                                                                1. Brightness vs Thermionic
                                                                2. Operating Conditions
                                                                  1. Temperature Control
                                                                    1. Vacuum Requirements
                                                                3. Comparison of Electron Sources
                                                                  1. Brightness
                                                                    1. Definition and Units
                                                                      1. Comparative Values
                                                                      2. Energy Spread
                                                                        1. Chromatic Effects
                                                                          1. Resolution Implications
                                                                          2. Lifetime and Maintenance
                                                                            1. Operational Lifetime
                                                                              1. Maintenance Requirements
                                                                                1. Cost Considerations
                                                                            2. Electromagnetic Lenses
                                                                              1. Condenser Lenses
                                                                                1. Beam Convergence Control
                                                                                  1. Convergence Angle Adjustment
                                                                                    1. Beam Current Control
                                                                                    2. Illumination Modes
                                                                                      1. Parallel Illumination
                                                                                        1. Convergent Illumination
                                                                                          1. Illumination Aperture Effects
                                                                                        2. Objective Lens
                                                                                          1. Image Formation
                                                                                            1. Primary Image Formation
                                                                                              1. Resolution Determination
                                                                                              2. Lens Design
                                                                                                1. Pole Piece Configuration
                                                                                                  1. Magnetic Field Distribution
                                                                                                  2. Aberration Contributions
                                                                                                    1. Spherical Aberration
                                                                                                      1. Chromatic Aberration
                                                                                                    2. Intermediate Lenses
                                                                                                      1. Magnification Adjustment
                                                                                                        1. Variable Magnification Control
                                                                                                          1. Image Rotation Effects
                                                                                                          2. Diffraction Pattern Formation
                                                                                                            1. Camera Length Control
                                                                                                              1. Pattern Magnification
                                                                                                            2. Projector Lenses
                                                                                                              1. Final Image Projection
                                                                                                                1. Screen or Detector Projection
                                                                                                                  1. Final Magnification Stage
                                                                                                                  2. Image Quality Considerations
                                                                                                                    1. Distortion Minimization
                                                                                                                      1. Resolution Preservation
                                                                                                                  3. Lens Aberrations and Corrections
                                                                                                                    1. Spherical Aberration
                                                                                                                      1. Physical Origin
                                                                                                                        1. Off-Axis Ray Focusing
                                                                                                                          1. Lens Field Non-Uniformity
                                                                                                                          2. Causes and Effects
                                                                                                                            1. Resolution Degradation
                                                                                                                              1. Image Blurring
                                                                                                                              2. Correction Methods
                                                                                                                                1. Aberration Corrector Design
                                                                                                                                  1. Multipole Correctors
                                                                                                                                2. Chromatic Aberration
                                                                                                                                  1. Energy Spread Effects
                                                                                                                                    1. Source Energy Spread
                                                                                                                                      1. Specimen Interactions
                                                                                                                                      2. Correction Techniques
                                                                                                                                        1. Monochromators
                                                                                                                                          1. Chromatic Aberration Correctors
                                                                                                                                        2. Astigmatism
                                                                                                                                          1. Origin and Causes
                                                                                                                                            1. Lens Manufacturing Imperfections
                                                                                                                                              1. Contamination Effects
                                                                                                                                              2. Correction Methods
                                                                                                                                                1. Stigmator Adjustments
                                                                                                                                                  1. Octupole Correctors
                                                                                                                                                2. Coma
                                                                                                                                                  1. Off-Axis Aberrations
                                                                                                                                                    1. Beam Tilt Effects
                                                                                                                                                      1. Lens Misalignment
                                                                                                                                                      2. Correction Approaches
                                                                                                                                                        1. Alignment Procedures
                                                                                                                                                          1. Coma Correctors
                                                                                                                                                        2. Distortion
                                                                                                                                                          1. Image Geometry Effects
                                                                                                                                                            1. Barrel and Pincushion Distortion
                                                                                                                                                              1. Measurement Accuracy Impact
                                                                                                                                                              2. Correction Methods
                                                                                                                                                                1. Software Correction
                                                                                                                                                                  1. Hardware Compensation
                                                                                                                                                                2. Aberration Correctors
                                                                                                                                                                  1. Types of Correctors
                                                                                                                                                                    1. Spherical Aberration Correctors
                                                                                                                                                                      1. Chromatic Aberration Correctors
                                                                                                                                                                      2. Impact on Resolution
                                                                                                                                                                        1. Sub-Angstrom Resolution Achievement
                                                                                                                                                                          1. Information Limit Extension
                                                                                                                                                                          2. Operational Considerations
                                                                                                                                                                            1. Stability Requirements
                                                                                                                                                                              1. Alignment Complexity
                                                                                                                                                                          3. Apertures
                                                                                                                                                                            1. Condenser Aperture
                                                                                                                                                                              1. Beam Current Control
                                                                                                                                                                                1. Aperture Size Effects
                                                                                                                                                                                  1. Illumination Intensity
                                                                                                                                                                                  2. Resolution Effects
                                                                                                                                                                                    1. Coherence Control
                                                                                                                                                                                      1. Diffraction Effects
                                                                                                                                                                                    2. Objective Aperture
                                                                                                                                                                                      1. Contrast Enhancement
                                                                                                                                                                                        1. Diffraction Contrast Control
                                                                                                                                                                                          1. Phase Contrast Effects
                                                                                                                                                                                          2. Diffraction Control
                                                                                                                                                                                            1. Beam Selection
                                                                                                                                                                                              1. Resolution vs Contrast Trade-offs
                                                                                                                                                                                            2. Selected Area Aperture
                                                                                                                                                                                              1. Area Selection for Diffraction
                                                                                                                                                                                                1. Specimen Area Definition
                                                                                                                                                                                                  1. Pattern Origin Control
                                                                                                                                                                                                  2. Applications in TEM
                                                                                                                                                                                                    1. Crystal Structure Analysis
                                                                                                                                                                                                      1. Phase Identification
                                                                                                                                                                                                  3. Vacuum Systems
                                                                                                                                                                                                    1. Purpose of High Vacuum
                                                                                                                                                                                                      1. Electron Scattering Reduction
                                                                                                                                                                                                        1. Mean Free Path Considerations
                                                                                                                                                                                                          1. Beam Quality Preservation
                                                                                                                                                                                                          2. Contamination Prevention
                                                                                                                                                                                                            1. Surface Cleanliness
                                                                                                                                                                                                              1. Specimen Integrity
                                                                                                                                                                                                            2. Vacuum Level Requirements
                                                                                                                                                                                                              1. Pressure Ranges for Different Microscopes
                                                                                                                                                                                                                1. SEM Vacuum Requirements
                                                                                                                                                                                                                  1. TEM Vacuum Requirements
                                                                                                                                                                                                                    1. FEG Vacuum Requirements
                                                                                                                                                                                                                  2. Pumping Systems
                                                                                                                                                                                                                    1. Roughing Pumps
                                                                                                                                                                                                                      1. Rotary Vane Pumps
                                                                                                                                                                                                                        1. Operating Principles
                                                                                                                                                                                                                          1. Oil Contamination Issues
                                                                                                                                                                                                                          2. Scroll Pumps
                                                                                                                                                                                                                            1. Dry Pumping Advantages
                                                                                                                                                                                                                              1. Performance Characteristics
                                                                                                                                                                                                                              2. Diaphragm Pumps
                                                                                                                                                                                                                                1. Oil-Free Operation
                                                                                                                                                                                                                                  1. Limited Pumping Speed
                                                                                                                                                                                                                                2. High Vacuum Pumps
                                                                                                                                                                                                                                  1. Turbomolecular Pumps
                                                                                                                                                                                                                                    1. Operating Principles
                                                                                                                                                                                                                                      1. Molecular Drag Mechanism
                                                                                                                                                                                                                                        1. Rotor Design
                                                                                                                                                                                                                                        2. Maintenance Requirements
                                                                                                                                                                                                                                          1. Bearing Replacement
                                                                                                                                                                                                                                            1. Rotor Balancing
                                                                                                                                                                                                                                          2. Ion Pumps
                                                                                                                                                                                                                                            1. Principle of Operation
                                                                                                                                                                                                                                              1. Ionization and Burial
                                                                                                                                                                                                                                                1. Magnetic Field Requirements
                                                                                                                                                                                                                                                2. Advantages and Limitations
                                                                                                                                                                                                                                                  1. Clean Vacuum
                                                                                                                                                                                                                                                    1. Limited Pumping Speed
                                                                                                                                                                                                                                                  2. Diffusion Pumps
                                                                                                                                                                                                                                                    1. Oil-Based Systems
                                                                                                                                                                                                                                                      1. Pump Fluid Selection
                                                                                                                                                                                                                                                        1. Backstreaming Issues
                                                                                                                                                                                                                                                        2. Oil-Free Types
                                                                                                                                                                                                                                                          1. Mercury Diffusion Pumps
                                                                                                                                                                                                                                                            1. Molecular Drag Pumps
                                                                                                                                                                                                                                                      2. Vacuum Gauges
                                                                                                                                                                                                                                                        1. Pirani Gauges
                                                                                                                                                                                                                                                          1. Thermal Conductivity Principle
                                                                                                                                                                                                                                                            1. Pressure Range and Accuracy
                                                                                                                                                                                                                                                            2. Ionization Gauges
                                                                                                                                                                                                                                                              1. Hot Cathode Gauges
                                                                                                                                                                                                                                                                1. Cold Cathode Gauges
                                                                                                                                                                                                                                                                  1. Pressure Range and Sensitivity
                                                                                                                                                                                                                                                                  2. Capacitance Manometers
                                                                                                                                                                                                                                                                    1. Absolute Pressure Measurement
                                                                                                                                                                                                                                                                      1. High Accuracy Applications
                                                                                                                                                                                                                                                                    2. Vacuum System Maintenance
                                                                                                                                                                                                                                                                      1. Leak Detection
                                                                                                                                                                                                                                                                        1. Helium Leak Detection
                                                                                                                                                                                                                                                                          1. Pressure Rise Testing
                                                                                                                                                                                                                                                                          2. Cleaning Procedures
                                                                                                                                                                                                                                                                            1. Bakeout Procedures
                                                                                                                                                                                                                                                                              1. Chemical Cleaning Methods
                                                                                                                                                                                                                                                                              2. Preventive Maintenance
                                                                                                                                                                                                                                                                                1. Pump Oil Changes
                                                                                                                                                                                                                                                                                  1. Seal Replacement

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                                                                                                                                                                                                                                                                            1. Fundamentals of Electron Microscopy

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                                                                                                                                                                                                                                                                            3. Transmission Electron Microscopy