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C. Br&hignac P. Houdy M. Lahmani (Eds.) Nanomaterials and Nanochemistry With 461 Figures and 26 Tables R 5 EUROPEAN MATERIALS RESEARCH SOCIETY ei Springer Contents Part I Basic Principles and Fundamental Properties 1 Size Effects on Structure and Morphology of Free or Supported Nanoparticles C. Henry 3 1.1 Size and Confinement Effects 3 1.1.1 Introduction 3 1.1.2 Fraction of Surface Atoms 3 1.1.3 Specific Surface Energy and Surface Stress 4 1.1.4 Effect on the Lattice Parameter 5 1.1.5 Effect on the Phonon Density of States 8 1.2 Nanoparticle Morphology 8 1.2.1 Equilibrium Shape of a Macroscopic Crystal 8 1.2.2 Equilibrium Shape of Nanometric Crystals 10 1.2.3 Morphology of Supported Particles 17 References 32 2 Structure and Phase Transitions in Nanocrystals J.-C. Niepce, L. Pizzagalli 35 2.1 Introduction 35 2.2 Crystalline Phase Transitions in Nanocrystals 39 2.2.1 Phase Transitions and Grain Size Dependence 39 2.2.2 Elementary Thermodynamics of the Grain Size Dependence of Phase Transitions 40 2.2.3 Influence of the Surface or Interface on Nanocrystals 42 2.2.4 Modification of Transition Barriers 44 2.3 Geometric Evolution of the Lattice in Nanocrystals 46 2.3.1 Grain Size Dependence 46 2.3.2 Theory 47 2.3.3 Influence of the Nanocrystal Surface or Interface on the Lattice Parameter 50 XII Contents 2.3.4 Is There a Continuous Variation of the Crystal State Within Nanocrystals? 51 References 53 3 Thermodynamics and Solid—Liquid Transitions P. Labastie, F. Calvo 55 3.1 Size Dependence of the Solid—Liquid Transition 56 3.1.1 From the Macroscopic to the Nanometric 56 3.1.2 From Nanoparticles to Molecules 64 3.2 Thermodynamics of Very Small Systems 67 3.2.1 General Considerations 67 3.2.2 Non-Equivalence of the Gibbs Ensembles 68 3.2.3 Dynamically Coexisting Phases 69 3.2.4 Stability of an Isolated Particle. Thermodynamic Equilibrium 73 3.3 Evaporation: Consequences and Observation 74 3.3.1 Statistical Theories of Evaporation 74 3.3.2 Link with the Solid—Liquid Transition. Numerical Results 79 3.3.3 Experimental Investigation of Evaporation 80 3.3.4 Beyond Unimolecular Evaporation 81 3.3.5 Toward the Liquid—Gas Transition 82 References 86 4 Modelling and Simulating the Dynamics of Nano-Objects A. Pimpinelli 89 4.1 Introduction 89 4.2 Free Clusters of Atoms. Molecular Dynamics Simulations 90 4.3 Evolution of Free and Supported Nanoclusters Toward Equilibrium. Kinetic Monte Carlo Simulations 93 References 97 Part II Physical and Chemical Properties an the Nanoscale 5 Magnetism in Nanomaterials D. Givord 101 5.1 Introduction 101 5.2 Magnetism in Matter 102 5.2.1 Magnetic Moment 102 5.2.2 Magnetic Order 105 5.2.3 Magnetocrystalline Anisotropy 108 5.3 Magnetisation Process and Magnetic Materials 110 5.3.1 Energy of the Demagnetising Field. Domains and Walls 111 5.3.2 The Magnetisation Process 112 5.3.3 Magnetic Materials 115 Contents XIII 5.4 Magnetism in Small Systems 116 5.4.1 Magnetic Moments in Clusters 116 5.4.2 Magnetic Order in Nanoparticles 119 5.4.3 Magnetic Anisotropy in Clusters and Nanoparticles 120 5.5 Magnetostatics and Magnetisation Processes in Nanoparticles 121 5.5.1 Single-Domain Magnetic Particles 121 5.5.2 Thermal Activation and Superparamagnetism 122 5.5.3 Coherent Rotation in Nanoparticles 123 5.5.4 From Thermal Activation to the Macroscopic Tunnel Effect 124 5.6 Magnetism in Coupled Nanosystems 126 5.6.1 Exchange-Coupled Nanocrystals. Ultrasoft Materials and Enhanced Remanence 126 5.6.2 Coercivity in Nanocomposites 128 5.6.3 Exchange Bias in Systems of Ferromagnetic Nanoparticles Coupled with an Antiferromagnetic Matrix 130 References 132 6 Electronic Structure in Clusters and Nanoparticles F. Spiegelman 135 6.1 Introduction 135 6.2 Liquid-Drop Model 139 6.3 Methods for Calculating Electronic Structure 141 6.3.1 Born—Oppenheimer Approximation. Surface Potential 142 6.3.2 Ab Initio Calculation of Electronic Structure 144 6.3.3 Density Functional Theory 147 6.3.4 Charge Analysis 149 6.3.5 Approximate and Semi-Empirical Descriptions 150 6.3.6 Energy Bands and Densities of States 152 6.4 Applications to Some Typical Examples 154 6.4.1 Metallic Nanoparticles 154 6.4.2 Molecular Clusters 162 6.4.3 Tonic and Ionocovalent Clusters 170 6.4.4 Covalent Systems 175 6.5 Valence Changes 178 6.5.1 Transitions with Size 178 6.5.2 Transitions with Stoichiometry 179 6.6 Nanotub es 182 6.7 Prospects 185 References 188 7 Optical Properties of Metallic Nanoparticles F. Valide 197 7.1 Optical Response for Free Clusters and Composite Materials 198 XIV Contents 7.2 Optical Response in the Quasi-Static Approximation: Nanospheres 199 7.3 Dielectric Constant of a Metal: Nanometric Size Effect 203 7.4 Surface Plasmon Resonance in the Quasi-Static Approximation: Nanospheres 207 7.5 Surface Plasmon Resonance: Quantum Effects for Small Sizes (D < 5 nm) 211 7.6 General Case for Nanospheres: The Mie Model 213 7.7 Non-Spherical or Inhomogeneous Nanoparticles in the Quasi-Static Model 216 7.7.1 Shape Effects: Ellipsoids 216 7.7.2 Structure Effects: Core–Shell System 217 7.8 Optical Response of a Single Metal Nanoparticle 219 7.9 Electromagnetic Field Enhancement: Applications 221 7.9.1 Nonlinear Optical Response 221 7.9.2 Time-Resolved Spectroscopy 222 7.9.3 Local Enhancement of Raman Scattering: SERS 223 7.10 Conclusion 224 References 226 8 Mechanical and Nanomechanical Properties C. Tromas, M. Verdier, M. Fivel, P. Aubert, S. Labdi, Z.-Q. Feng, M. Zei, P. Joli 229 8.1 Macroscopic Mechanical Properties 229 8.1.1 Introduction 229 8.1.2 Elastic Properties 229 8.1.3 Hardness 231 8.1.4 Ductility 234 8.1.5 Numerical Modelling 236 8.2 Nanomechanical Properties 238 8.2.1 Experimentation 238 8.2.2 Computer Modelling 254 References 265 9 S up erplast icity T. Rouxel 269 9.1 Introduction 269 9.2 Mechanism 270 9.3 Superplastic Nanostructured Materials 276 9.4 Industrial Applications 277 References 280 Contents XV 10 Reactivity of Metal Nanoparticles J.-C. Bertolini, J.-L. Rousset 281 10.1 Size Effects 282 10.1.1 Structural Properties 282 10.1.2 Electronic Pfoper-Hes 286 10.1.3 Reactivity in Chemisorption and Catalysis of Monometallic Nanoparticles 288 10.2 Support Effects 293 10.3 Alloying Effects 295 10.3.1 Effect of Surface Segregation 296 10.3.2 Geometric Effects 297 10.3.3 Electronic Effects 298 10.4 Preparation and Implementation in the Laboratory and in Industry 299 References 302 11 Inverse Systems — Nanoporous Solids J. Patarin, 0. Spalla, F. Di Renzo 305 11.1 Introduction 305 11.2 Nomenclature: The Main Families of Porous Materials 305 11.3 Zeolites and Related Microporous Solids. Definition and Structure 307 11.4 Ordered Mesoporous Solids 309 11.5 Disordered Nanoporous Solids 311 References 314 12 Inverse Systems — Confined Fluids: Phase Diagram and Metastability E. Charlaix, R. Denoyel 315 12.1 Displacement of First Order Transitions: Evaporation and Condensation 315 12.1.1 Adsorption Isotherms 315 12.1.2 Capillary Condensation 317 12.1.3 Capillary Pressure and the Kelvin Radius 319 12.1.4 Non-Wetting Fluid 320 12.1.5 Perfectly Wetting Fluid 320 12.1.6 Hysteresis, Metastability and Nucleation 322 12.2 Melting—Solidification 325 12.3 Modification of the Critical Temperature 329 12.4 Ultraconfinement: Microporous Materials 331 References 334 XVI Contents 13 Supramolecular Chemistry: Applications and Prospects N. Solladie, J.-F. Nierengarten 335 13.1 From Molecular to Supramolecular Chemistry 335 13.2 Molecular Recognition 335 13.3 Anionic Coordination Chemistry and Recognition of Anionic Substrates 338 13.4 Multiple Recognition 338 13.5 Applications 341 13.6 Prospects 343 References 344 14 Nanocomposites: The End of Compromise H. Van Damme 347 14.1 Composites and Nanocomposites 347 14.2 Introduction to Polymers 351 14.2.1 Ideal Chains 352 14.2.2 The Glass Transition 354 14.2.3 Entropie Elasticity 357 14.3 Nanofillers 359 14.3.1 Clays 359 14.3.2 Carbon Nanotubes 363 14.4 Strengthening and Permeability Control: Models 364 14.4.1 Strengthening: Increasing the Modulus 364 14.4.2 Impermeability: Reducing the Diffusivity 367 14.5 Strengthening and Permeability of Nanocomposites: Facts and Explanations 369 14.5.1 Strengthening: Successes and Failures 369 14.5.2 Impermeability 376 14.5.3 Dimensional Stability 377 14.5.4 Fire Resistance 379 14.6 Conclusion 379 References 380 Part III Synthesis of Nanomaterials and Nanoparticles 15 Specific Features of Nanoscale Growth J. Livage, D. Roux 383 15.1 Introduction 383 15.2 Thermodynamics of Phase Transitions 383 15.3 Dynamics of Phase Transitions 385 15.3.1 Thermodynamics of Spinodal Decomposition 386 15.3.2 Thermodynamics of NucleationGrowth 388 15.4 Size Control 389 15.5 Triggering the Phase Transition 391 Contents XVII 15.6 Application to Solid Nanoparticles 392 15.6.1 Controlling Nucleation 392 15.6.2 Controlling Growth 393 15.6.3 Controlling Aggregation. Stability of Colloidal Dispersions 393 15.7 Breaking Matter into Pieces 393 References 394 16 Gas Phase Synthesis of Nanopowders Y. Champion 395 16.1 Introduction 395 16.2 The Need for Gas State Processing 397 16.3 Main Stages of Gas Phase Synthesis 400 16.4 Spontaneous Condensation of Nanoparticles: Homogeneous Nucleation 401 16.5 Undesirable Post-Condensation Effects and Control of the Nanometric State 408 16.5.1 Why Do These Effects Occur? 409 16.5.2 Particle Growth by Gas Condensation 410 16.5.3 Coalescent Coagulation 411 16.6 Vapour Formation and the Production of Nanopowders 416 16.6.1 Physical Processes 416 16.6.2 Chemical Processing: Laser Pyrolysis 424 16.7 Conclusion 426 References 426 17 Synthesis of Nanocomposite Powders by Gas–Solid Reaction and by Precipitation C.
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