ISBN: 3540676813
TITLE: Progress in Transmission Electron Microscopy 2
AUTHOR: Zhang, Zhang (Eds.)
TOC:

1 The Guidance Role of HRTEM in Developing Mesoporous Molecular Sieves 1
1.1 Introduction 1
1.2 Formation of Uniform Mesopores 2
1.3 The HRTEM Technique 3
1.4 MCM-41 5
1.5 Metal Clusters i n MCM-41 11
1.6 SBA-2 17
1.7 STAC-1 20
1.8 Prospective Development 22
References 23
2 HREM Study of Carbon Nanoclusters Grown from Carbon Arc-Discharge 25
2.1 Fullerenes and Carbon Nanotubes 25
2.2 Structures of Individual Carbon Nanotubes 28
2.3 Single-Walled Nanotubes (SWNTs) 42
2.4 Microstructure of the Star Pattern 47
2.5 Strings of Carbon Nanobeads 51
2.6 Encapsulation of Foreign Materials into Carbon Nanoclusters 56
2.7 Conversion of Carbon Nanotubes into Silicon Carbide Whiskers 65
References 68
3 Determining the Helicity of Carbon Nanotubes by Electron Diffraction 73
3.1 Introduction 73
3.2 Structure Description 76
3.2.1 Crystallographic Notations 76
3.2.2 Structural Parameters 77
3.3 Theoretical Background 79
3.3.1 Electron Imaging 79
3.3.2 Electron Diffraction 81
3.4 Measurement of True Helicity 87
3.4.1 Isolated Single-Walled Carbon Nanotubes 89
3.4.2 Raft-Like Bundles of Single-Walled Carbon Nanotubes 95
3.4.3 Multiwalled 97
3.5 Discussion 97
3.5.1 Diffraction Symmetry 97
3.5.2 Tilt and Measurement 98
3.5.3 Calculation of Tubule Structure Factors 99
3.6 Concluding Remarks 99
Appendix 100
References 102
4 Low Dimensional Materials and Their Microstructures Studied by High Resolution Electron Microscopy 105
4.1 Introduction 105
4.2 Boron Nitride Nanotubes 106
4.2.1 Fabrication 106
4.2.2 HREM Study 107
4.3 Silicon Nanowires 112
4.3.1 Experimentals 113
4.3.2 Microstructure 114
4.4 Giant Magneto-Resistance and Metallic Multi-Layers 118
4.4.1 Spin-Dependent Scattering 119
4.4.2 Two-Fluid Model for the GMR of Multilayer Systems 120
4.4.3 Parameters Influencing the GMR 122
4.4.4 Mismatch Between Magnetic/Nonmagnetic Layers 123
4.4.5 Fe/MO Magnetic Multi-Layers 125
4.4.6 NiFe/Mo Magnetic Multi-Layers 133
4.5 GaN Thin Films 144
4.5.1 Background 144
4.5.2 Structure of GaN and Sapphire 145
4.5.3 Crystal Growth of GaN Thin Films 147
4.5.4 Phase Variation in the GaN Buffer Layer 148
4.5.5 Microstructure of GaN Buffer Layers 154
4.5.6 GaN Buffer Layer Evolution During the Two-Step Growth Process 158
4.5.7 Formation of Domain Boundaries in the Epitaxial Layers of GaN 161
4.5.8 Conclusions 165
References 165
5 Microstructures of High-T_c Superconducting Josephson Junctions 171
5.1 Introduction 171
5.2 TEM Sample Preparation 173
5.3 Microstructures of Thin Films on Various Substrates 177
5.3.1 Starting Atomic Layer 178
5.3.2 Surface Atomic Layer and Nonunit-Cell Growth 183
5.3.3 On Inclined Surface 186
5.3.4 Mismatch and Epitaxy 187
5.4 Grain Boundary (GB) Junctions 188
5.4.1 Bicrystal Junction 188
5.4.2 a/c Grain Boundary Junction 195
5.4.3 Step-Edge Junctions 196
5.4.4 Groove-Type Focused-Ion Beam Junction 197
5.5 Artificial Barrier Junctions 199
5.5.1 Planar Junction 199
5.5.2 Ramp-Edge Junction 201
5.5.3 Interface-Engineered Junction 204
5.5.4 Homoepitaxy 206
Summary 209
References 209
6 Swift Heavy Ion Irradiation Damage in YBa_2Cu_3O_7-delta Superconductors 213
6.1 Introduction 213
6.2 Experimental Procedure 216
6.3 Cross Section Images 218
6.3.1 Entry Surface 218
6.3.2 Variation of Track Diameter with Depth 219
6.3.3 Variation of Angular Splay in Depth 221
6.3.4 Fluctuations in the Damaged Structure 224
6.4 Plan-View Images 227
6.4.1 Local Oxygen Re-Ordering in Low Dose (<1T) Irradiated Sample 227
6.4.2 Relaxed Strain Field by the Oxygen Re-Ordering 231
6.4.3 Nano Twin Network in Higher Dose (-2T) Irradiated Sample 235
6.5 Discussion 240
6.6 Conclusion 243
References 243
7 Transmission Electron Microscopy Investigations of Misfit Dislocations in Lattice-Mismatched Semiconductor Heterostructures 247
7.1 Introduction 247
7.2 Sources of Misfit Dislocations and Their Generation Mechanisms 250
7.3 Determination of Critical Thickness of Misfit Dislocation Generation 253
7.4 Misfit Dislocation Configurations 255
7.4.1 The Equilibrium Geometry of 60 Dissociated Misfit Dislocations 255
7.4.2 Misfit Dislocation Configurations Due to Interactions 257
7.4.3 Partial Misfit Dislocations 260
7.4.4 Unusual Misfit Dislocation Configurations 260
7.4.5 Misfit Dislocation Configurations in the High-Strain Case 262
7.5 Conclusion 263
References 264
8 Dislocation Contrast Analysis: a Study of delta' Heterogeneous Nucleation on Dislocations 267
8.1 Introduction 267
8.2 Analytical Considerations 269
8.2.1 The Theory 269
8.2.2 The g.b Criteria for Determining the Burgers Vector Direction 271
8.2.3 The (g.b)s Criterion for Determining the Sense of Dislocations Based on the FS/RH Convention 272
8.2.4 Computer Simulation of a Straight Dislocation Image 275
8.3 Experimental Examples 277
8.3.1 A Brief Background 277
8.3.2 delta'Nucleation on Straight Dislocations 278
8.3.3 delta'Nucleation on a Dislocation Network 280
8.4 Conclusions 285
References 285
9 Transmission Electron Cryomicroscopy and Three-Dimensional Reconstruction of Macromolecular Complexes 287
9.1 Introduction 287
9.2 Overview of Methods 288
9.2.1 Image Formation and Correction 290
9.2.2 Specimen Thickness and Number of Views Needed 290
9.3 Data Processing 291
9.3.1 Common-Lines 291
9.3.2 Orientation and Center Determination 293
9.3.3 3D Projection Matching or Model-Based Refinement 294
9.3.4 "Common-Plane" Method 295
9.3.5 Methods of 3D Reconstruction 295
9.4 Examples of Macromolecular Complex Structures 296
9.4.1 Icosahedral Virus 296
9.4.2 Difference Imaging of Particles at Different Functional States 299
9.4.3 Non-icosahedral Single Particles 299
9.4.4 Utility of Stain Structure 300
9.4.5 Atomic Structures by Electron Crystallography of 2D Crystals 301
References 302
Index 305
END
