High Thermal Conductivity Materials

Contents......Page 9
Preface......Page 6
Contributors......Page 15
1.1 Introduction......Page 17
1.2 Theory of Thermal Conductivity......Page 18
1.2.1 Green-Kubo Linear-Response Theory......Page 19
1.2.2 Variational Principles......Page 20
1.2.3 Relaxation-Time Approaches......Page 22
1.3.1 Three-Dimensional Materials......Page 24
1.3.2 Graphite, Graphene, and Nanotubes......Page 27
1.3.3 Debye’s Isotropic Continuum Model......Page 31
1.4 Phonon Relaxation Times......Page 32
1.4.1 Extrinsic Relaxation Times......Page 33
1.4.2 Intrinsic Relaxation Times......Page 34
1.5.1 Simplified Conductivity Integral......Page 37
1.5.3 High-Thermal-Conductivity Materials......Page 38
1.5.4 Conductivity of Diamond-Structure Single Crystals......Page 39
1.6 Conductivity of Polycrystalline Solids......Page 41
1.7.1 Superlattices......Page 42
1.7.2 Semiconductor Quantum Wells and Wires......Page 43
1.7.3 Graphite, Graphene, Carbon Nanotubes, and Fullerenes......Page 45
1.8 Summary......Page 49
2.1 Introduction: The Importance of Thermal Conductivity......Page 52
2.2.1 Normal Modes of Vibrations of a Lattice......Page 54
2.2.2 Normal and Umklapp Phonon-Scattering Processes......Page 57
2.2.4 Callaway Model......Page 58
2.2.6 Extension to More Complex Crystal Structures and Criteria for High Thermal Conductivity......Page 59
2.3.1 Rocksalt, Diamond, and Zincblende Crystal Structures......Page 60
2.3.2 Wurtzite Crystal Structure......Page 63
2.3.3 Silicon Nitride and Related Structures......Page 65
2.3.5 Graphite and Related Materials......Page 69
2.4 Thermal Conductivity of Wide-Band-Gap Semiconductors: Silicon Carbide, Aluminum Nitride, and Gallium Nitride......Page 72
2.5 Isotope Effect in High Lattice Thermal Conductivity Materials......Page 77
2.6 Summary......Page 79
3.1 Introduction......Page 84
3.2.1 CVD Diamond......Page 87
3.2.3 Aluminum Nitride (AlN)......Page 90
3.3 Overview of the Measurement Techniques......Page 92
3.3.1 The Heating and Thermometry Techniques......Page 93
3.3.2 Measurement Time Scale......Page 94
3.3.3 Impact of Geometry on Thermal Property Measurements in the Transient Techniques......Page 95
3.4 Steady-State Techniques......Page 98
3.4.1 The Heated Suspended Bar Technique......Page 100
3.4.2 The Film-on-Substrate Technique......Page 103
3.4.3 The DC Heated Suspended Membrane......Page 106
3.4.4 The Comparator Method......Page 110
3.5 Frequency-Domain Techniques......Page 112
3.5.1 The Ångström Thermal Wave Technique......Page 113
3.5.2 The Modified Calorimetric Method......Page 114
3.5.3 The High-Thermal-Conductivity Films on the Low-Thermal-Conductivity Substrates......Page 116
3.5.4 Thermal Characterization of the Anisotropic Silicon-Nitride Substrates......Page 117
3.5.5 Thermal Characterization of the AlN Substrates with Spatially Variable Thermal Conductivity......Page 119
3.5.6 The Mirage Technique......Page 121
3.6.1 The Laser Heating Method......Page 122
3.6.3 The Thermal Grating Technique......Page 126
3.7 Summary......Page 127
4.1 Introduction......Page 134
4.2.2 Plane and Spherical Thermal Waves......Page 135
4.2.4 Thermal Waves and Photothermal Setups......Page 137
4.2.5 Analysis of the Experimental Data......Page 138
4.3.1 Determination of the Thermal Diffusivity with the Mirage Experiment......Page 143
4.3.3 Aluminium Nitride Ceramics......Page 145
4.3.5 Thermal Heterogeneïty Evidence on Diamond Samples......Page 147
4.4.1 Photothermal Microscope......Page 148
4.4.2 Thermal Diffusivity Measurement at a Single Grain Scale......Page 149
4.4.4 Thermal Barrier Evidence on AlN Ceramics......Page 151
4.4.5 Very Thin Layer Thermal Property Determination......Page 153
4.5 Conclusion......Page 156
5.1 Theoretical Basis......Page 158
5.2 Procedures for the Fabrication of High-Thermal-Conductivity Aluminum Nitride Ceramics......Page 161
5.3 Phase Equilibria, Sintering, and Thermodynamic Considerations......Page 163
5.3.1 Free Energies of Formation and the Activity of Al[sub(2)]O[sub(3)]......Page 166
5.3.2 Thermodynamics of Oxygen Removal and the Analysis of Thermal Conductivity......Page 169
5.3.3 Kinetics of Oxygen Removal and Microstructural Changes......Page 170
5.3.4 Long-Term Annealing and Microstructural Changes......Page 176
5.4 Summary......Page 179
6.1 Introduction......Page 182
6.2 CVD-SiC Process......Page 184
6.3 Properties of CVD-SiC......Page 188
6.3.1 Thermal Properties......Page 192
6.3.2 Mechanical Properties......Page 197
6.3.4 Optical Properties......Page 200
6.4.1 Thermal Management and Semiconductor Processing Applications......Page 204
6.4.2 Optics and Wear Applications......Page 206
6.5 Summary and Conclusions......Page 209
7.1 Introduction......Page 214
7.2 Diamond Synthesis by CVD......Page 217
7.2.1 Postdeposition Processing......Page 221
7.3 Properties of CVD Diamond......Page 223
7.3.1 Thermal Conductivity of Diamond......Page 224
7.3.2 Thermal Shock Resistance......Page 234
7.4 High-Thermal-Conductivity Applications......Page 235
7.4.2 Optics and Other Applications......Page 236
7.5 Summary and Conclusions......Page 237
8.1 Introduction......Page 242
8.2 Theory of Energy Conduction in Carbon Nanotubes......Page 243
8.2.1 Phonons in Carbon Nanotubes......Page 246
8.2.2 Computational Methods......Page 252
8.2.3 Thermal Conductivity of Carbon Nanotubes......Page 257
8.3 Experiments of Thermal Conduction in Carbon Nanotubes......Page 261
8.3.1 Bulk Thermal-Conductivity Measurements of Carbon Nanotubes......Page 262
8.3.2 Experimental Method for the Mesoscopic Thermal Transport Measurement......Page 267
8.3.3 Thermal Conductivity of Multiwalled Nanotubes......Page 272
8.4 Summary and Future Work......Page 277
D......Page 281
L......Page 282
S......Page 283
T......Page 284
Z......Page 285