Tài liệu Cấu trúc và tính chất nano nguyên tử

Contents
Foreword vii
Acknowledgments xv
1 . Introduction to Clusters 1
1.1 The Field of Clusters 1
1.2 Types of Clusters 3
1.2.1 Van der Waals clusters 3
1.2.2 Metal clusters 4
1.2.3 Clusters of ionic materials . 5
1.2.4 Network clusters 6
1.2.5 Cluster assembled solids 6
References 6
2 . Experimental Production of Clusters 7
2.1 Formation of Clusters in Matrices 7
2.1.1 Chemical reaction in a liquid medium . 7
2.1.2 Irradiation of a solid 8
2.1.4 Condensation on a substrate 9
2.3 Ion Bombardment . 10
2.4.1 Kinetics of coagulation 12
2.4.2 Seeded nozzle sources . 13
2.4.3 Gas aggregation sources 13
2.4.4 Laser vaporization . 14
2.1.3 Immersion of a porous glass in a liquid metal . 9
2.2 Liquid Metal Ion Source . 10
2.4 Supersonic Nozzle Sources 10
2.4.5 Clusters in helium droplets 14
2.5 Mass Analysis . 14
References 18
ix
X Structure and Properties of Atomic Clusters
3 . Van der Waals Clusters 21
3.1 Structure of Van der Waals Clusters 21
3.3 Thermal Properties . 31
3.3.1 Solid to solid transitions 31
3.2 Transition to the Bulk . 28
3.3.2 Melting transition 33
3.3.3 Mixed inert gas clusters . 42
3.3.4 Liquid to gas phase transition in hydrogen clusters 43
3.4 Electronic Effects . 46
3.4.2 Core level spectroscopy . 50
3.5 Clusters of SF6 and C02 Molecules 52
3.4.1 Delocalized electronic states of excess electrons 46
3.6 Interaction with Ultrafast Laser Pulses . 54
References 56
4 . Electronic and Atomic Shells in Metal Clusters . 59
4.1 Experimental Observation of Electronic Shells 59
4.2 Spherical Well Model of Metallic Clusters 62
4.3 Electronic Shell Effects in Large Clusters 69
4.4 Spheroidal Deformations of the Cluster Shape 74
4.5 A Full Description of the Cluster Structure 77
4.6 Shells of Atoms 83
4.7 Approximate Treatment of the Geometrical Structure . 86
4.7.1 Spherically Averaged Pseudopotential Model 86
Model 88
4.8 Clusters of the Aluminum Group . 89
References 92
4.7.2 Cylindrically Averaged Pseudopotential (CAPS)
4.8.1 Aluminum clusters . 89
4.8.2 Boron clusters 91
5 . Electronic and Optical Properties of Simple Metal Clusters 97
5.1 Ionization Potential and Electron Affinity 97
5.3 Temperature Dependence of the Ionization Potential 108
5.4 Hardness and Reactivity . 110
5.5 Mass Spectrum Obtained at Near-Threshold Ionization
5.6 Response to a Static Electric Field . 116
5.2 Odd-Even Effects . 104
Energies 113
Contents xi
5.7 Dynamical Response 120
5.7.1 Relation between theory and experiment 120
5.7.2 Sum rules . 124
5.7.3 Calculation of the dynamical susceptibility . 128
5.7.4 Spherical clusters . 130
5.7.5 Effect of shape deformations . 135
5.7.6 Effect of the ion granularity 138
5.7.7 Vibrational structure of the optical response . 143
5.7.8 Thermal line broadening 145
References 147
6 . Melting and Fragmentation of Metal Clusters 153
6.1 Melting Transition 153
6.1.1 Experiments for large alkali clusters . 153
size clusters . 156
6.1.2 Calorimetric measurements of melting of medium
6.2 Computer Simulation of Melting 162
6.2.1 Computer simulations using approximate methods . 162
6.2.2 Ab initio simulations 168
6.4 Optical Properties and Melting . 175
6.3 Clusters with Abnormally High Melting Temperature . 170
6.5 Fragmentation of Multiply Charged Clusters .1 76
6.5.1 Surface and Coulomb forces . 176
6.5.2 Models and calculations of cluster fission . 179
6.6 Optical Response Along the Fission Path . 191
6.7 From Fission to Fragmentation to Coulomb Explosion . 193
6.8 Caloric Curves of Fragmenting Clusters 198
References 200
7 . Bimetallic Clusters . 205
7.1 Introduction 205
7.3 Collective Electronic Excitations . 208
Clusters . 210
7.5 Higher Valence Impurities 215
7.6 Impurities in Aluminum Clusters . 220
References 225
7.2 Alloying Effects in Alkali Metal Clusters 205
7.4 Divalent and Monovalent Impurities in Alkali Metal
xii Structure and Properties of Atomic Clusters
8 . Clusters of the Transition Metals 229
8.1 Noble Metal Clusters 229
8.1.1 Electronic shell effects 229
8.1.2 Interplay between d and s electrons . 231
8.1.3 Structure 232
8.1.4 Special properties of gold clusters . 234
8.1.5 Optical properties 236
8.2 General Bonding Properties in Clusters of Transition
8.3 Electronic and Atomic Structure 240
8.3.1 Nickel clusters . 241
Metals . 238
8.3.2 Iron clusters . 244
8.3.3 Niobium clusters 245
8.3.4 Titanium and Vanadium clusters . 248
8.3.5 Chromium clusters . 250
8.4 Thermionic Emission from Refractory Metal Clusters 253
8.5 Nonmetal to Metal Transition . 256
8.6 Atomic Shell Effects . 259
8.6.1 Reactivity of Ni clusters 260
8.7 Gold Clusters with Impurities . 266
8.6.2 Shell effects in other clusters . 265
8.8 Doubly Charged Clusters 268
References 270
9 . Magnetism 277
9.1 Some Basic Concepts . 277
9.3 Magnetic Shell Models . 282
9.4 Temperature Dependence of the Magnetic Moments . 287
Interpretation 289
9.5.1 Tight-binding studies . 289
9.5.2 Influence of the s electrons 298
9.6 Density Functional Studies for Ni, Fe and Cr Clusters 299
9.6.1 Nickel clusters . 299
9.6.2 Iron and and Chromium clusters . 300
9.7 Experiments and Calculations for Mn Clusters 301
9.7.1 Clusters with less than ten atoms . 301
9.7.2 Clusters with more than ten atoms 305
9.2 Size Dependence of the Magnetic Moments 279
9.5 Magnetic Moments of Nickel Clusters and their
Contents xiii
9.8 Magnetism in Clusters of the 4d Metals . 306
9.8.2 Ruthenium and Palladium clusters 309
9.9 Effect of Adsorbed Molecules 310
Theory and Photodetachment Spectroscopy . 312
9.1 1 Noncollinear Magnetism 314
9.8.1 Rhodium clusters . 307
9.10 Determination of Magnetic Moments by Combining
References 316
10 . Clusters of Ionic Materials . 321
10.1 Nearly Stoichiometric Metal Halide Clusters . 321
10.2 Nonstoichiometric Metal Halide Clusters 325
10.4 Structural Transitions . 329
10.3 Small Neutral Clusters 326
References 332
11 . Carbon Clusters 333
11.1 Carbon Fullerenes . 333
1 1.1 . 1 Discovery of the fullerenes 333
11.1.2 Electronic structure of CG0 . 336
11.1.3 Other fullerenes . 338
1 1.2 Fullerene Collisions 340
11.2.1 Collisions at medium to high energies 341
11.2.2 Collisions at low to medium energies . 342
1 1.2.3 Collisions with surfaces . 342
1 1.3.1 Alkali metal coverage 343
11.4.1 Fullerenes 348
11.4.2 Medium size clusters . 350
11.4.3 Coated fullerenes . 352
1 1.4.4 Multilayered fullerenes 353
11 S.1 Structure and infrared vibrational spectroscopy 355
11.5.2 Other physical properties of metcars . 359
11 S.3 Chemical reactivity 360
1 1.3 Coating of Fullerenes . 343
11.3.2 Coverage by other metals 345
11.4 Optical Properties of Carbon Clusters . 348
1 1.5 Metalcarbohedrenes 355
xiv Structure and Properties of Atomic Clusters
12 .
1 1.6 Other Metal-Carbon Clusters: from Small Clusters to
Nanocrystals 361
References 364
Assembling of New Materials from Clusters . 369
12.1 General Principles 369
12.2 Crystalline Intermetallic Compounds Containing
Clusters . 371
12.3 Boron Clusters in Solids . 376
12.4.1 (C60)N clusters 378
12.4 Assembling of C60 Fullerenes . 378
12.4.2 Fullerene solids 383
12.4.3 Alkali-doped fullerene solids 385
12.4.4 Melting in assemblies of c60 clusters 387
12.5 Simulations of the Assembling of Doped Aluminum
Clusters to Form Clustered Materials . 391
12.5.1 AllzX clusters with 40 valence electrons . 391
12.5.2 Assembling of AlI3H clusters 393
12.5.3 Assembling of superionic cluster-solids 396
References 397
Index . 401