Noncontact Atomic Force Microscopy (eBook)

Preface 6
Contents 8
List of Contributors 15
1 Introduction 19
1.1 Rapidly Developing High Performance AFM 19
1.1.1 Present Status of High Performance AFM 22
NC-AFM Spatial Resolution Beyond STM 22
Chemical Coordination Effect in NC-AFM Topographic Image 22
Mechanical Atom Manipulation Under Nearcontact Region 25
1.2 Future Prospects for High Performance AFM 26
1.2.1 Atomic and Molecular Imaging in Liquids 26
1.2.2 Magnetic Exchange Force Microscopy 26
1.2.3 Rapid Growth of Tuning Fork/qPlus Sensor 29
1.2.4 Differentiation of Atomic Force 29
1.2.5 Atom-by-Atom Assembly of Complex Nanostructure at RT 30
References 31
2 Method for Precise Force Measurements 32
2.1 Quantitative Force Calculation 32
2.2 Thermal Drift 33
2.3 Three-Fold Feedback for Precise Tip–Sample Positioning 33
2.3.1 Principle of Atom-Tracking 34
2.3.2 Experimental Setup 35
2.3.3 Site-Specific Force Spectroscopy at Room Temperature 37
2.4 Thermal Drift Compensation for Force Field Mapping 40
2.4.1 Concept of Feedforward 40
2.4.2 Force Mapping at Room Temperature with Feedforward 41
2.4.3 Force Mapping with Feedforward 43
Example 1: Numerical Analysis for Potential and Lateral Force 43
Example 2: Surface Atom Discrimination 45
2.5 Summary 46
References 46
3 Force Spectroscopy on Semiconductor Surfaces 48
3.1 Introduction 48
3.2 Experimental Considerations 50
3.2.1 Extraction of the Short-Range Forcefrom the Frequency Shift 51
3.2.2 Determination of Relevant Acquisition Parameters 53
3.3 Energy Dissipation and Force Spectroscopy 55
3.3.1 Tip-Apex Characterization Combining Force Spectroscopy and First-Principles Calculations 55
3.3.2 Identification of an Energy Dissipation Channel 59
3.3.3 Surface Adhesion Maps at Atomic Scale 62
3.3.4 Signatures of Energy Dissipation in Frequency Shiftand Force Curves 63
3.4 Force Spectroscopy and Atomic Relaxations 65
3.5 Single Atom Chemical Identification 70
3.6 Force Spectroscopy with Higher Flexural Modes 78
3.7 Summary 82
Acknowledgments 82
References 83
4 Tip–Sample Interactions as a Function of Distance on Insulating Surfaces 86
4.1 Experimental Evaluation of Short-range Forces 87
4.1.1 Measurement Techniques 87
4.1.2 Conversion of Frequency Shift to Force 89
4.1.3 Separation of Short-range and Long-range Forces 90
4.2 Short-range Forces on Insulating Surfaces 93
4.2.1 Simple Model for Electrostatic Forces 93
4.2.2 Relaxation and Realistic Electrostatic Interactions 95
4.2.3 Interaction of a Tip with a Well-known Surface 97
4.2.4 Sublattice Identification on Alkali Halide Surfaces 99
4.2.5 Full Three-Dimensional Force Field 100
4.2.6 Atomic Jumps and Energy Dissipation 103
Acknowledgement 109
References 109
5 Force Field Spectroscopy in Three Dimensions 112
5.1 Introduction 112
5.2 Three-Dimensional Force FieldSpectroscopy: The Technique 114
5.2.1 Experimental Set-up 114
5.2.2 The Interrelation Between Frequency Shiftand Tip–Sample Forces 117
5.2.3 Extending Dynamic Force Spectroscopyto Three Dimensions 119
5.3 Force Field Spectroscopy on Ionic Crystals 121
5.3.1 Force Fields and Energy Dissipation on NaCl 121
5.3.2 Force Vector Fields on KBr 127
5.4 True 3D Force Field Spectroscopy on Graphite 130
Acknowledgements 133
References 134
6 Principles and Applications of the qPlus Sensor 137
6.1 Motivation: qPlus Versus Si Cantilever 137
6.1.1 Specifications of an Atomic Force Probe 138
6.1.2 Cantilevers in Dynamic Force Microscopy 140
6.1.3 Advantages of Small Amplitude Operation 141
6.1.4 Ideal Physical Properties of Cantilevers 144
6.2 Theory of qPlus Versus Tuning Fork Sensors 144
6.2.1 Quartz Tuning Forks 144
6.2.2 qPlus Sensor 147
6.2.3 Manufacturing High Quality qPlus Sensors 148
6.2.4 Preamplifiers for qPlus Sensors 150
6.3 Applications 153
6.3.1 Own Results 153
6.3.2 External Groups 154
6.4 Outlook 154
Acknowledgment 156
References 156
7 Study of Thin Oxide Films with NC-AFM:Atomically Resolved Imaging and Beyond 159
7.1 Introduction 159
7.2 Methods and Experimental Setup 161
7.2.1 Quartz Tuning Fork-based Sensor for Dual-Mode NC-AFM/STM 161
7.2.2 Concepts for Force and Energy Extraction and Sensor Characterization 164
7.3 Atomic Resolution Imaging 166
7.4 Beyond Imaging: Spectroscopy 172
7.4.1 z-Spectroscopy on Specific Atomic Sites 173
7.4.2 Work Function Shift Measurements 176
7.5 Conclusion 181
Acknowledgements 181
References 181
8 Atom Manipulation on Semiconductor Surfaces 184
8.1 Introduction 184
8.2 Experimental 186
8.3 Vertical Atom Manipulation 187
8.4 Lateral Atom Manipulation at Low Temperature 188
8.5 Interchange Lateral Atom Manipulation 190
8.6 Lateral Atom Manipulation at Room Temperature 194
8.7 Interchange Vertical Atom Manipulation 199
8.8 Summary 203
Acknowledgement 203
References 204
9 Atomic Manipulation on Metal Surfaces 206
9.1 Introduction 207
9.2 Modes of Manipulation 208
9.3 Instrumentation 210
9.3.1 Detected Signals 212
9.4 Forces During Adsorbate Manipulating 214
9.4.1 Manipulating a Small Molecule: CO on Cu(111) 221
9.5 Modeling Forces and Conductance 222
9.6 Mapping the Energy Landscape 224
9.7 Summary 228
Acknowledgments 228
References 228
10 Atomic Manipulation on an Insulator Surface 231
10.1 Introduction 232
10.2 Basic Principles 232
10.2.1 Experimental Procedures 232
10.2.2 Surface Characterization 233
10.3 Experimental Results 235
10.3.1 Defect Preparation and Contrast Formation 235
10.3.2 Manipulation of Mobile Defects 237
10.3.3 Velocity Dependence of Manipulation 239
10.4 Conclusions 239
Acknowledgments 240
References 240
11 Basic Mechanisms for Single Atom Manipulation in Semiconductor Systems with the FM-AFM 241
11.1 Introduction 241
11.2 Theoretical Approach: First-PrinciplesSimulations 243
11.3 The Short Range Chemical Interaction Between Tip and Sample 244
11.4 Manipulation in the Attractive Regime: Vacanciesin the Si(111)-(77) Reconstruction 246
11.5 Manipulation in the Repulsive Tip–Surface Interaction Regime 251
11.5.1 A Complex Phase Space Under Strong Tip–Surface Interactions 251
11.5.2 Dip-Pen Atomic Lithography: Vertical AtomInterchange Between the Tip and the Surfacein the -Sn/Si(111)-(33) Surface 254
11.6 Conclusion 261
Acknowledgements 262
References 262
12 Multi-Scale Modelling of NC-AFM Imaging and Manipulation at Insulating Surfaces 264
12.1 Introduction 264
12.2 Methods 266
12.2.1 Modelling the Instrument 266
12.2.2 Modelling the Tip–Surface Junction 267
12.2.3 Kinetic Monte Carlo 269
12.3 Applications 271
12.3.1 Pd Adatom on MgO (001) 271
12.3.2 H2O Adsorbate on CeO2 (111) 276
12.3.3 C60 on Si (001) 278
12.4 Discussion 283
Acknowledgements 284
References 285
13 Magnetic Exchange Force Microscopy 287
13.1 Introduction 287
13.2 Tip Preparation 289
13.3 NiO(001) 290
13.4 Fe/W(001) 294
13.5 Future Perspectives 297
References 297
14 First-Principles Simulation of Magnetic Exchange Force Microscopy on Fe/W(001) 299
14.1 Introduction 299
14.2 Computational Method 301
14.3 Analysis of the Magnetic Exchange Forces 303
14.3.1 Unrelaxed Tip and Sample 303
14.3.2 Influence of Structural Relaxations 305
14.3.3 Electronic and Magnetic Structure Changesdue to Tip–Sample Interaction 306
14.3.4 Influence of Tip Size 307
14.4 Simulation of MExFM Images 309
14.5 Summary 311
References 312
15 Frequency Modulation Atomic Force Microscopy in Liquids 314
15.1 Brief Overview 314
15.2 Problems of Frequency Modulation AFMin Liquids 315
15.2.1 Viscous Damping of Cantilever in Fluid 315
15.2.2 Electric Double Layer Force 318
15.3 Frequency Noise in Frequency ModulationAtomic Force Microscopy 319
15.3.1 Basics of Frequency Modulation 319
15.3.2 Frequency Noise Analysis in High-Q Environment 321
15.3.3 Frequency Noise Analysis in Low-Q Environment 325
15.4 Improvement of FM-AFM for Liquid Environment 327
15.4.1 Optimization of Optical Beam Deflection Sensor 327
15.4.2 Reduction of Coherence Length of Laser 329
15.4.3 Reduction of Oscillation Amplitude 331
15.5 High-Resolution Imaging by FM-AFM in Liquid 332
15.5.1 Muscovite Mica 332
15.5.2 Purple Membrane Proteins 334
15.5.3 Isolated Protein Molecules 334
15.5.4 Measurement of Local Hydration Strcutres 336
15.6 Summary and Outlook 337
References 338
16 Biological Applications of FM-AFM in Liquid Environment 340
16.1 Quantitative Force Measurements 340
16.1.1 Calculating Force from Frequency Shift 340
16.1.2 Cantilever Excitation in Liquid 341
16.1.3 Single Molecule Spectroscopy 343
16.2 Subnanometer-Resolution Imaging 344
16.2.1 Overview 344
16.2.2 Technical Progresses 347
16.2.3 Biological Applications 349
Hydration Layers 349
Lipid-Ion Network 350
Amyloid Fibrils 353
16.3 Future Prospects 354
References 355
17 High-Frequency Low Amplitude Atomic Force Microscopy 357
17.1 Cantilever 357
17.2 Cantilever Vibration Excitation 358
17.3 Cantilever Vibration Detection 361
17.4 AFM Head 362
17.5 Control Scheme 364
17.6 Imaging with Small Amplitude of Drive 365
17.7 Lateral Dynamic Force Microscopy 366
17.8 Summary 368
References 369
18 Cantilever Dynamics and Nonlinear Effects in Atomic Force Microscopy 371
18.1 Introduction 371
18.2 Eigenmodes of AFM Cantilevers 373
18.2.1 Eigenmodes of Tipless Microcantilevers 373
18.2.2 Influence of Tip Mass on AFM Cantilever Eigenmodes 375
18.2.3 Eigenmodes of Triangular AFM Microcantilevers 376
18.3 Cantilever Dynamics in AM-AFM 378
18.3.1 Mathematical Simulations of Cantilever Dynamics 378
18.3.2 Single Mode Nonlinear Phenomena in dAFM:Bifurcations, Higher Harmonics, and Chaos 380
18.3.3 Multimode Nonlinear Dynamics in dAFM 385
18.3.4 Cantilever Dynamics in Liquids 386
18.4 Cantilever Dynamics in FM-AFM 389
18.4.1 Origins of Frequency Shift and Its Measurement 390
18.4.2 Selecting Probes for FM-AFM 393
18.4.3 Dynamic Characteristics of High FrequencyCantilevers and Tuning Forks 395
18.4.4 Higher Harmonics in FM-AFM 398
18.4.5 FM-AFM Under Liquids 399
18.5 Outlook 399
References 401
Index 406