Preface ........................................................ xv
1. Physics of Bulk Solids ....................................... 1
1.1. Structure ............................................... 1
1.1.1. Size Dependence of Properties .................... 1
1.1.2. Crystal Structures ............................... 2
1.1.3. Face-Centered Cubic Nanoparticles ................ 7
1.1.4. Large Face-Centered Cubic Nanoparticles .......... 9
1.1.5. Tetrahedrally Bonded Semiconductor
Structures ...................................... 10
1.1.6. Lattice Vibrations .............................. 14
1.2. Surfaces of Crystals ................................... 16
1.2.1. Surface Characteristics ......................... 16
1.2.2. Surface Energy .................................. 17
1.2.3. Face-Centered Cubic Surface Layers .............. 18
1.2.4. Surfaces of Zinc Blende and Diamond
Structures ...................................... 21
1.2.5. Adsorption of Gases ............................. 23
1.2.6. Electronic Structure of a Surface ............... 25
1.2.7. Surface Quantum Well ............................ 26
1.3. Energy Bands ........................................... 26
1.3.1. Insulators, Semiconductors, and Conductors ...... 26
1.3.2. Reciprocal Space ................................ 27
1.3.3. Energy Bands and Gaps of Semiconductors ......... 28
1.3.4. Effective Mass .................................. 34
1.3.5. Fermi Surfaces .................................. 35
1.4. Localized Particles .................................... 36
1.4.1. Donors, Acceptors, and Deep Traps ............... 36
1.4.2. Mobility ........................................ 37
1.4.3. Excitons ........................................ 38
Problems .................................................... 40
References .................................................. 41
2. Methods of Measuring Properties of Nanostructures ........... 43
2.1. Introduction ........................................... 43
2.2. Structure .............................................. 44
2.2.1. Atomic Structures ............................... 44
2.2.2. Crystallography ................................. 45
2.2.3. Particle Size Determination ..................... 50
2.2.4. Surface Structure ............................... 54
2.3. Microscopy ............................................. 54
2.3.1. Transmission Electron Microscopy ................ 54
2.3.2. Field Ion Microscopy ............................ 59
2.3.3. Scanning Microscopy ............................. 59
2.4. Spectroscopy ........................................... 66
2.4.1. Infrared and Raman Spectroscopy ................. 66
2.4.2. Photoemission, X-Ray, and Auger Spectroscopy .... 72
2.4.3. Magnetic Resonance .............................. 78
2.5. Various Bulk Properties ................................ 81
2.5.1. Mechanical Properties ........................... 81
2.5.2. Electrical Properties ........................... 81
2.5.3. Magnetic Properties ............................. 82
2.5.4. Other Properties ................................ 82
Problems .................................................... 82
References .................................................. 83
3. Properties of Individual Nanoparticles ...................... 85
3.1. Introduction ........................................... 85
3.2. Metal Nanoclusters ..................................... 86
3.2.1. Magic Numbers ................................... 86
3.2.2. Theoretical Modeling of Nanoparticles ........... 88
3.2.3. Geometric Structure ............................. 91
3.2.4. Electronic Structure ............................ 94
3.2.5. Reactivity ...................................... 97
3.2.6. Fluctuations ................................... 100
3.2.7. Magnetic Clusters .............................. 100
3.2.8. Bulk-to-Nano Transition ........................ 103
3.3. Semiconducting Nanoparticles .......................... 104
3.3.1. Optical Properties ............................. 104
3.3.2. Photofragmentation ............................. 106
3.3.3. Coulomb Explosion .............................. 107
3.4. Rare-Gas and Molecular Clusters ....................... 107
3.4.1. Inert-Gas Clusters ............................. 107
3.4.2. Superfluid Clusters ............................ 108
3.4.3. Molecular Clusters ............................. 109
3.4.4. Nanosized Organic Crystals ..................... 111
3.5. Methods of Synthesis .................................. 111
3.5.1. RF Plasma ...................................... 111
3.5.2. Chemical Methods ............................... 111
3.5.3. Thermolysis .................................... 112
3.5.4. Pulsed-Laser Methods ........................... 114
3.5.5. Synthesis of Nanosized Organic Crystals ........ 114
3.6. Summary ............................................... 118
Problems .............................................. 118
4. The Chemistry of Nanostructures ............................ 121
4.1. Chemical Synthesis of Nanostructures .................. 121
4.1.1. Solution Synthesis ............................. 121
4.1.2. Capped Nanoclusters ............................ 122
4.1.3. Solgel Processing .............................. 124
4.1.4. Electrochemical Synthesis of Nanostructures .... 125
4.2. Reactivity of Nanostructures .......................... 125
4.3. Catalysis ............................................. 127
4.3.1. Nature of Catalysis ............................ 127
4.3.2. Surface Area of Nanoparticles .................. 127
4.3.3. Porous Materials ............................... 131
4.4. Self-Assembly ......................................... 135
4.4.1. The Self-Assembly Process ...................... 135
4.4.2. Semiconductor Islands .......................... 136
4.4.3. Monolayers ..................................... 139
Problems ................................................... 141
5. Polymer and Biological Nanostructures ...................... 143
5.1. Polymers .............................................. 143
5.1.1. Polymer Structure .............................. 143
5.1.2. Sizes of Polymers .............................. 146
5.1.3. Nanocrystals of Polymers ....................... 148
5.1.4. Conductive Polymers ............................ 151
5.1.5. Block Copolymers ............................... 152
5.2. Biological Nanostructures ............................. 154
5.2.1. Sizes of Biological Nanostructures ............. 154
5.2.2. Polypeptide Nanowire and Protein
Nanoparticles .................................. 160
5.2.3. Nucleic Acids .................................. 162
5.2.3.1. DNA Double Nanowire ................... 162
5.2.3.2. Genetic Code and Protein Synthesis .... 166
5.2.3.3. Proteins .............................. 167
5.2.3.4. Micelles and Vesicles ................. 169
5.2.3.5. Multilayer Films ...................... 172
Problems ................................................... 174
References ................................................. 174
6. Cohesive Energy ............................................ 177
6.1. Ionic Solids .......................................... 177
6.2. Defects in Ionic Solids ............................... 183
6.3. Covalently Bonded Solids .............................. 185
6.4. Organic Crystals ...................................... 186
6.5. Inert-Gas Solids ...................................... 190
6.6. Metals ................................................ 191
6.7. Conclusion ............................................ 193
Problems ................................................... 193
7. Vibrational Properties ..................................... 195
7.1. The Finite One-Dimensional Monatomic Lattice .......... 195
7.2. Ionic Solids .......................................... 197
7.3. Experimental Observations ............................. 199
7.3.1. Optical and Acoustical Modes ................... 199
7.3.2. Vibrational Spectroscopy of Surface Layers
of Nanoparticles ............................... 201
7.3.2.1. Raman Spectroscopy of Surface
Layers ................................ 201
7.3.2.2. Infrared Spectroscopy of Surface
Layers ................................ 201
7.4. Phonon Confinement .................................... 207
7.5. Effect of Dimension on Lattice Vibrations ............. 209
7.6. Effect of Dimension on Vibrational Density of
States ................................................ 211
7.7. Effect of Size on Debye Frequency ..................... 215
7.8. Melting Temperature ................................... 216
7.9. Specific Heat ......................................... 218
7.10.Plasmons .............................................. 220
7.11.Surface-Enhanced Raman Spectroscopy ................... 222
7.12.Phase Transitions ..................................... 223
Problems ................................................... 226
References ................................................. 227
8. Electronic Properties ...................................... 229
8.1. Ionic Solids .......................................... 229
8.2. Covalently Bonded Solids .............................. 232
8.3. Metals ................................................ 234
8.3.1.Effect of Lattice Parameter on Electronic
Structure ...................................... 235
8.3.2. Free-Electron Model ............................ 235
8.3.3. The Tight-Binding Model ........................ 239
8.4. Measurements of Electronic Structure of
Nanoparticles ......................................... 242
8.4.1. Semiconducting Nanoparticles ................... 242
8.4.2. Organic Solids ................................. 248
8.4.3. Metals ......................................... 250
Problems ................................................... 251
9. Quantum Wells, Wires, and Dots ............................. 253
9.1. Introduction .......................................... 253
9.2. Fabricating Quantum Nanostructures .................... 253
9.2.1. Solution Fabrication ........................... 254
9.2.2. Lithography .................................... 257
9.3. Size and Dimensionality Effects ....................... 261
9.3.1. Size Effects ................................... 261
9.3.2. Size Effects on Conduction Electrons ........... 263
9.3.3. Conduction Electrons and Dimensionality ........ 264
9.3.4. Fermi Gas and Density of States ................ 265
9.3.5. Potential Wells ................................ 268
9.3.6. Partial Confinement ............................ 272
9.3.7. Properties Dependent on Density of States ...... 273
9.4. Excitons .............................................. 275
9.5. Single-Electron Tunneling ............................. 276
9.6. Applications .......................................... 280
9.6.1. Infrared Detectors ............................. 280
9.6.2. Quantum Dot Lasers ............................. 280
Problems ................................................... 285
References ................................................. 285
10.Carbon Nanostructures ...................................... 287
10.1.Introduction .......................................... 287
10.2.Carbon Molecules ...................................... 287
10.2.1.Nature of the Carbon Bond ...................... 287
10.2.2.New Carbon Structures .......................... 289
10.3.Carbon Clusters ....................................... 289
10.3.1.Small Carbon Clusters .......................... 289
10.3.2.Buckyball ...................................... 292
10.3.3.The Structure of Molecular C60 ................. 293
10.3.4.Crystalline C60 ................................ 296
10.3.5.Larger and Smaller Buckyballs .................. 300
10.3.6.Buckyballs of Other Atoms ...................... 300
10.4.Carbon Nanotubes ...................................... 301
10.4.1. Fabrication ................................... 301
10.4.2.Structure ...................................... 304
10.4.3.Electronic Properties .......................... 306
10.4.4.Vibrational Properties ......................... 312
10.4.5.Functionalization .............................. 314
10.4.6.Doped Carbon Nanotubes ......................... 322
10.4.7.Mechanical Properties .......................... 325
10.5.Nanotube Composites ................................... 327
10.5.1.Polymer-Carbon Nanotube Composites ............. 327
10.5.2.Metal-Carbon Nanotube Composites ............... 329
10.6.Graphene Nanostructures ............................... 330
Problems .............................................. 335
11.Bulk Nanostructured Materials .............................. 337
11.1.Solid Methods for Preparation of Disordered
Nanostructures ........................................ 337
11.1.1.Methods of Synthesis ........................... 337
11.1.2.Metal Nanocluster Composite Glasses ............ 340
11.1.3.Porous Silicon ................................. 343
11.2.Nanocomposites ........................................ 347
11.2.1.Layered Nanocomposites ......................... 347
11.2.2.Nanowire Composites ............................ 349
11.2.3.Composites of Nanoparticles .................... 350
11.3.Nanostructured Crystals ............................... 351
11.3.1.Natural Nanocrystals ........................... 351
11.3.2.Crystals of Metal Nanoparticles ................ 352
11.3.3.Arrays of Nanoparticles in Zeolites ............ 355
11.3.4.Nanoparticle Lattices in Colloidal
Suspensions .................................... 357
11.3.5.Computational Prediction of Cluster
Lattices ....................................... 358
11.4.Electrical Conduction in Bulk Nanostructured
Materials ............................................. 359
11.4.1.Bulk Materials Consisting of Nanosized
Grains ......................................... 359
11.4.2.Nanometer-Thick Amorphous Films ................ 364
11.5.Other Properties ...................................... 364
Problems .............................................. 365
12.Mechanical Properties of Nanostructured Materials .......... 367
12.1.Stress-Strain Behavior of Materials ................... 367
12.2.Failure Mechanisms of Conventional Grain-Sized
Materials ............................................. 370
12.3.Mechanical Properties of Consolidated Nano-Grained
Materials ............................................. 371
12.4.Nanostructured Multilayers ............................ 374
12.5.Mechanical and Dynamical Properties of Nanosized
Devices ............................................... 376
12.5.1.General Considerations ......................... 376
12.5.2.Nanopendulum ................................... 378
12.5.3.Vibrations of a Nanometer String ............... 380
12.5.4.The Nanospring ................................. 381
12.5.5.The Clamped Beam ............................... 382
12.5.6.The Challenges and Possibilities of
Nanomechanical Sensors ......................... 385
12.5.7.Methods of Fabrication of Nanosized Devices .... 387
Problems .............................................. 390
13.Magnetism in Nanostructures ................................ 393
13.1.Basics of Ferromagnetism .............................. 393
13.2.Behavior of Powders of Ferromagnetic Nanoparticles .... 398
13.2.1.Properties of a Single Ferromagnetic
Nanoparticle ................................... 398
13.2.2.Dynamics of Individual Magnetic
Nanoparticles .................................. 400
13.2.3.Measurements of Superparamagnetism and the
Blocking Temperature ........................... 402
13.2.4.Nanopore Containment of Magnetic Particles ..... 405
13.3.Ferrofluids ........................................... 406
13.4.Bulk Nanostructured Magnetic Materials ................ 413
13.4.1.Effect of Nanosized Grain Structure on
Magnetic Properties ............................ 413
13.4.2.Magnetoresistive Materials ..................... 416
13.4.3.Carbon Nanostructured Ferromagnets ............. 424
13.5.Antiferromagnetic Nanoparticles ....................... 429
Problems .............................................. 430
14.Nanoelectronics, Spintronics, Molecular Electronics,
and Photonics .............................................. 433
14.1.Nanoelectronics ....................................... 433
14.1.1.N and P Doping and PN Junctions ................ 433
14.1.2.MOSFET ......................................... 435
14.1.3.Scaling of MOSFETs ............................. 436
14.2.Spintronics ........................................... 440
14.2.1.Definition and Examples of Spintronic
Devices ........................................ 440
14.2.2.Magnetic Storage and Spin Valves ............... 440
14.2.3.Dilute Magnetic Semiconductors ................. 445
14.3.Molecular Switches and Electronics .................... 449
14.3.1.Molecular Switches ............................. 449
14.3.2.Molecular Electronics .......................... 453
14.3.3.Mechanism of Conduction through a Molecule ..... 458
14.4.Photonic Crystals ..................................... 459
Problems .............................................. 465
Reference ............................................. 466
15.Superconductivity in Nanomaterials ......................... 467
15.1.Introduction .......................................... 467
15.2.Zero Resistance ....................................... 467
15.2.1.The Superconducting Gap ........................ 469
15.2.2.Cooper Pairs ................................... 470
15.3.The Meissner Effect ................................... 472
15.3.1.Magnetic Field Exclusion ....................... 472
15.3.2.Type I and Type II Superconductors ............. 474
15.4.Properties of Flux .................................... 478
15.4.1.Quantization of Flux ........................... 478
15.4.2.Vortex Configurations .......................... 479
15.4.3.Flux Creep and Flux Flow ....................... 480
15.4.4.Vortex Pinning ................................. 484
15.5.Dependence of Superconducting Properties
on Size Effects ....................................... 484
15.6.Resistivity and Sheet Resistance ...................... 484
15.7.Proximity Effect ...................................... 488
15.8.Superconductors as Nanomaterials ...................... 490
15.9.Tunneling and Josephson Junctions ..................... 491
15.9.1.Tunneling ...................................... 491
15.9.2.Weak Links ..................................... 491
15.9.3.Josephson Effect ............................... 493
15.9.4.Josephson Junctions ............................ 494
15.9.5.Ultrasmall Josephson Junctions ................. 494
15.10.Superconducting Quantum Interference Device
(Squid) ............................................... 495
15.11.Buckministerfullerenes ............................... 496
15.11.1.The Structure of C60 and Its Crystal .......... 496
15.11.2.Alkali-Doped C60 .............................. 496
15.11.3.Superconductivity in C60 ...................... 497
Problems ................................................... 498
References ................................................. 499
Appendix A. Formulas for Dimensionality ....................... 501
A.l. Introduction ................................. 501
A.2. Derealization ................................ 501
A.3. Square and Parabolic Wells ................... 502
A.4. Partial Confinement .......................... 503
Appendix В. Tabulations of Semiconducting Material
Properties ........................................ 507
Appendix С. Face-Centered Cubic and Hexagonal Close-Packed
Nanoparticles ..................................... 515
C.l. Introduction ................................. 515
C.2. Face-Centered Cubic Nanoparticles ............ 515
C.3. Hexagonal Close-Packed Nanoparticles ......... 519
Index ......................................................... 521
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