The first single-source reference to all the major features of LEAP tomography, this volume includes a wealth of practical tips and covers all four core aspects of a LEAP tomography experiment from start to finish, as well as the software methods employed.

This book is the first, single-source guide to successful experiments using the local electrode atom probe (LEAP ® ) microscope. Coverage is both comprehensive and user friendly, including the fundamentals of preparing specimens for the microscope from a variety of materials, the details of the instrumentation used in data collection, the parameters under which optimal data are collected, the current methods of data reconstruction, and selected methods of data analysis. Tricks of the trade are described that are often learned only through trial and error, allowing users to succeed much more quickly in the challenging areas of specimen preparation and data collection. A closing chapter on applications presents selected, state-of-the-art results using the LEAP microscope.

Written from the user perspective by the developers of the instrument themselves

Covers the main features of a local electrode atom probe tomography experiment from start to finish

Contains practical hints and tutorial information that is useful to any atom probe operator to improve the chances of a successful analysis

Includes a chapter on hardware/instrumentation, which explains to the novice user the various parts of the instrument and how they operate

Provides an overview of the software methods employed in LEAP, including reconstruction and data analysis

Includes supplementary material: sn.pub/extras

Inhalt

Preface
Acknowledgements
Foreword
Abbreviations

Chapter 1. History of APT and LEAP
1.1 Introduction
1.2 Ancestry of the Local Electrode Atom Probe
1.2.1 Early History and the Field Electron Emission Microscope (~1935)
1.2.2 Field Ion Microscope: The First Images of Atoms (1955)
1.2.3 Atom Probe Field Ion Microscope (1967)
1.2.4 The Advent of Atom Probe Tomography
1.2.5 The Position Sensitive Atom Probe (1988)
1.2.6 Electron Beam Pulsed Atom Probe
1.2.7 The Scanning Atom Probe
1.2.8 The Local Electrode Atom Probe (2001)
1.3 The State of Instrumentation
1.3.1 The Growth of the Local Electrode Atom Probe
1.3.2 Laser Pulsing
1.3.3 Fundamental Considerations for Design of Instrumentation
1.3.4 Reflectron-Based Instruments
1.4 FIB-Based Specimen Preparation
1.5 Concluding Remarks
References

Chapter 2. Specimen Preparation
2.1 Introduction
2.2 Electropolishing
2.3 Needles versus Microtips
2.4 Electrostatic Discharge Considerations
2.5 Focused Ion Beam Methods
2.5.1 Capping Considerations & Damage
2.5.2 Standard Lift-Out Process
2.5.3 Sharpening Process
2.5.4 FIB Deprocessing
2.6 Hybrid Transmission Electron Microscopy / Atom Probe Tomography
2.7 Summary
References

Chapter 3. Design & Instrumentation
3.1 Introduction
3.2 How Atom Probes Work
3.3 LEAP Performance Parameters
3.3.1 Field of View
3.3.2 Mass Resolving Power
3.3.3 Data Collection Rate
3.3.4 Model Comparison
3.4. Instrumentation in the LEAP
3.4.1 Local Electrode
3.4.2 Detection and Imaging
3.4.3. Transfer and Storage of Consumables
3.4.4. Field Evaporation Systems
3.4.5 Ancillary Systems
3.5 Summary
References

Chapter 4. Data Collection
4.1 Introduction
4.2 Data Quality Considerations
4.3 Analysis Yield Considerations
4.4 Experimental Parameters
4.5 How to Start Your Investigation of Any New Material
4.6 Brief Overview of LEAP Operation: Data Collection
4.6.1 Voltage Acquisition
4.6.2 Laser Acquisition
4.6.3 Now You Are Atom Probing
References

Chapter 5. Data Processing and Reconstruction
5.1 Introduction
5.2 A Word on Data Files and Work Flow
5.3 Conversion from Detector Space to Specimen Space Coordinates
5.3.1 Selection of Depth and Areal Regions
5.3.2 Spectral Calibration
5.3.3 Chemical Identification & Ranging
5.3.4 Spatial Reconstruction: Projection and Depth Scaling
5.3.5 Wide Angle Reconstruction Protocols
5.3.6 Tangential Discontinuity
5.3.7 Reconstruction Explorer
5.3.8 Creation of ROOT and POS Files
5.4 Discussion of Spatial Resolution and Spatial Positioning
5.4.1 Spatial Resolution
5.4.2 Spatial Positioning (Non-Specimen Dependent)
5.4.3 Spatial Positioning (Specimen Dependent)
5.5 A Word on Density Relaxation
5.6 Reconstruction Case Study: NIST Standard Reference Material 2134
5.6.1 Reconstruction Parameter Discussion
5.6.2 Experiment and Analysis Details
References

Chapter 6. Selected Analysis Topics
6.1 Introduction
6.2 Spectral Analysis
6.2.1 Ranging
6.2.2 Practical Considerations for Detection Levels
6.2.3 Peak Decomposition
6.3 Concentration Space Analyses
6.3.1 Gridding, Voxels, and Delocalization
6.3.2 Interface Creation and Interfacial Roughness
6.3.3 Effects of Delocalization on Planar Surfaces
6.3.4 The Proximity Histogram
6.4 Solute Analysis: Cluster Detection Method
6.5 Spatial Distribution Maps
6.6 Application of Spatial Distribution Maps
References

Chapter 7. Applications of the Local Electrode Atom Probe
7.1 Metals
7.2 Catalytic Materials
7.3 Ceramic and Geological Materials
7.4 Semiconductor Materials
7.5 Organics and Biological Materials
7.6 Composite Structures/Devices
7.7 Conclusions
References

Appendix A. Data File Formats
Appendix B. Field Evaporation
Appendix C. Reconstruction Geometry
Appendix D. Mass Spectral Performance
Appendix E. Additional Considerations for LEAP Operation

Glossary

Index