Scanning Tunneling Microscopy II

1. Introduction.- 1.1 STM in Electrochemistry and Biology.- 1.2 Probing Small Forces on a Small Scale.- 1.3 Related Scanning Probe Microscopies.- 1.4 Nanotechnology.- References.- 2. STM in Electrochemistry.- 2.1 Principal Aspects.- 2.2 Experimental Concepts for Electrolytic STM at Potential-Controlled Electrodes.- 2.2.1 Potential Control Circuitry, STM Cell Design, Counter and Reference Electrodes.- 2.2.2 Tunneling Tips.- 2.2.3 Sample Preparation and Transfer Procedures.- 2.3 Electrochemical Applications of In Situ STM at Potential-Controlled Electrodes.- 2.3.1 STM Studies at Metal Electrodes.- 2.3.2 STM Studies at Carbon and Semiconductor Electrodes.- 2.3.3 Miscellaneous Investigations.- 2.4 Outlook.- References.- 3. The Scanning Tunneling Microscope in Biology.- 3.1 Instrumentation.- 3.1.1 The STM Head.- 3.1.2 Auxiliary Microscopes.- 3.1.3 Electronics.- 3.1.4 Controlling the Environment of the STM Head.- 3.1.5 Tunneling Tips.- 3.2 Processing of STM Images.- 3.2.1 Correction of Imaging Faults.- 3.2.2 Evaluation of STM Images.- 3.2.3 Representation of the Images.- 3.3 Preparation.- 3.3.1 Substrates.- 3.3.2 Specimen Deposition.- 3.3.3 Specimen Dehydration.- 3.3.4 Coating with Conductive Films.- 3.3.5 Examining the Quality of Preparations.- 3.4 Applications.- 3.4.1 Nucleic Acids.- 3.4.2 Proteins.- 3.4.3 Biological Membranes.- 3.5 Imaging and Conduction Mechanisms.- 3.5.1 Practical Observations in STM Imaging of Uncoated Biological Material.- 3.5.2 Measurements of Conductivity and Related Parameters.- 3.5.3 Basic Electron Transfer Mechanisms.- 3.5.4 Intrinsic Conduction in Organic and Biological Material: Theoretical Considerations.- 3.5.5 External Conduction Mechanisms.- 3.5.6 Image Formation.- 3.6 Conclusions.- References.- 4. Scanning Force Microscopy (SFM).- 4.1 Experimental Aspects of Force Microscopy.- 4.1.1 Preparations of Cantilevers.- 4.1.2 Techniques to Measure Small Cantilever Deflections.- 4.1.3 Modes of Operation.- 4.2 Forces and Their Relevance to Force Microscopy.- 4.2.1 Forces Between Atoms and Molecules.- 4.2.2 Forces in Relation to Scanning Force Microscopy.- 4.3 Microscopic Description of the Tip—Sample Contact.- 4.3.1 Empirical Potentials.- 4.3.2 Molecular Dynamics.- 4.3.3 Continuum Elasticity Theory.- 4.3.4 Ab Initio Calculations.- 4.4 Imaging with the Force Microscope.- 4.4.1 SFM on Layered Materials.- 4.4.2 Ionic Crystals.- 4.4.3 Organic Molecules.- 4.4.4 Applications of SFM on a Nanometer Scale.- 4.5 Conclusions and Outlook.- References.- 5. Magnetic Force Microscopy (MFM).- 5.1 Basic Principles of MFM.- 5.2 Measurement Techniques.- 5.2.1 Force Detection.- 5.2.2 Force Gradient Detection.- 5.2.3 Deflection Sensors.- 5.2.4 Servo Considerations.- 5.3 Force Sensors.- 5.3.1 Basic Properties.- 5.3.2 Electrochemically Etched Tips.- 5.3.3 Tips Coated with Magnetic Thin Films.- 5.4 Theory of MFM Response.- 5.4.1 Magnetic Interaction.- 5.4.2 Image Simulation.- 5.4.3 Mutual Disturbance of Tip and Sample.- 5.5 Imaging Data Storage Media.- 5.5.1 Longitudinal Magnetic Recording Media.- 5.5.2 Modeling Longitudinal Media.- 5.5.3 Magnetic Recording Studies.- 5.5.4 Magneto-Optic Recording Media.- 5.6 Imaging Soft Magnetic Materials.- 5.6.1 Iron Whiskers.- 5.6.2 NiFe (Permalloy).- 5.6.3 Tip—Sample Interactions.- 5.7 Resolution.- 5.7.1 Experimental Results.- 5.7.2 Theoretical Considerations.- 5.8 Separation of Magnetic and Topographic Signals.- 5.9 Comparison with Other Magnetic Imaging Techniques.- 5.10 Conclusions and Outlook.- References.- 6. Related Scanning Techniques.- 6.1 Historical Background.- 6.2 STM and Electrical Measurements.- 6.2.1 Basic Principle of STM.- 6.2.2 Scanning Noise Microscopy and Scanning Tunneling Potentiometry.- 6.3 STM and Optical Effects.- 6.3.1 Optical Rectification and Scanning Photon Microscope.- 6.3.2 STM and Inverse Photoemission Microscopy.- 6.4 Near-Field Thermal Microscopy.- 6.5 Scanning Force Microscopy and Extensions.- 6.6 Conclusion.- References.- 7. Nano-optics and Scanning Near-Field Optical Microscopy.- 7.1 Nano-optics: Optics of Nanometer-Size Structures.- 7.1.1 General Considerations.- 7.1.2 Theoretical Approach.- 7.1.3 Gap Fields and Tip Plasmons.- 7.1.4 Pointed Tips as Near-Field Optical Probes.- 7.1.5 Spherical Particle Above Substrate.- 7.1.6 Nano-Apertures.- 7.1.7 Dipole Above Ground.- 7.2 Experimental Work.- 7.2.1 SNOM Designs.- 7.2.2 Aperture/Transmission.- 7.2.3 Aperture/Reflection.- 7.2.4 Protrusion/Reflection.- 7.2.5 Pointed Transparent Fiber/Transmission.- 7.2.6 The Photon-Emitting STM.- 7.2.7 Basic NFO Experiments.- 7.2.8 Aperture/Transmission.- 7.2.9 Aperture/Reflection.- 7.2.10 Protrusion/Reflection.- 7.2.11 Pointed Optical Fiber (PSTM, STOM).- 7.2.12 Pointed Metal Tip.- 7.3 Plasmons and Spectroscopic Effects.- 7.3.1 Protrusions: Influence of Particle Size.- 7.3.2 Apertures: Enhanced Spectroscopy.- 7.4 Imaging by SNOM.- 7.4.1 Transmission.- 7.4.2 Reflection/Aperture.- 7.4.3 Reflection/Protrusion.- 7.4.4 Optical Fiber (PSTM, STOM).- 7.4.5 SNOM-Type Imaging with the STM.- 7.5 Discussion, Outlook, Conclusions.- 7.5.1 Problems Solved.- 7.5.2 Open Questions, Comparison of Different Methods.- 7.5.3 Outlook.- References.- 8. Surface Modification with a Scanning Proximity Probe Microscope.- 8.1 Overview.- 8.2 Microfabrication with a Scanning Probe Microscope.- 8.2.1 A Universal Approach.- 8.2.2 Discussion of the Basic Parameters.- 8.3 Investigation of the Fabrication Process.- 8.3.1 Indirect Investigations.- 8.3.2 Direct Investigations.- 8.3.3 Response of Different Samples and Environments.- 8.4 Review of SXM Lithography.- 8.4.1 Exposure of an Electron or Photo-Resist.- 8.4.2 Mechanical Machining.- 8.4.3 Deposition.- 8.4.4 Thermal Treatment.- 8.4.5 Decomposition of Organometallic Gases.- 8.4.6 Manipulation of Molecules and Atoms.- 8.4.7 Electrochemical and Photoelectrochemical Processes.- 8.4.8 Ion and Electron Etching.- 8.4.9 Modifications of Indeterminate Origin.- References.