The purpose of the present survey is to review the analysis of composite materials from the applied mechanics and engineering science point of view. The subjects under consideration will be analysis of the following properties of various kinds of composite materials: elasticity, thermal expansion, moisture swelling, viscoelasticity, conductivity (which includes, by mathematical analogy, dielectrics, magnetics, and diffusion) static strength, and fatigue failure.

Analysis of Composite Materials—A Survey

Thick films will be defined here as those sufficiently thick to permit evolutionary selection processes during growth to influence their structures. High rates are defined as those sufficient to deposit thick films in a reasonable time. To avoid superficiality, this review is restricted to evaporation and sputtering, i.e. to physical vapor deposition (PVD). PVD is finding increased use for applications ranging from micro­ electronics to corrosion-barrier and wear-resistant coatings, and to the synthesis of free-standing shapes with unique mechanical properties. The emphasis here is on metallic deposits and on the physics of their growth and structure. Particular attention is given to sputtering, because recent developments ih sputtering tech­ nology make thick film deposition feasible, and because the subject has not been reviewed. Several reviews have concentrated on thick film deposition by evaporation (1, 2). Structure zone models (3-5) [particularly the model proposed by Movchan & Demchishin (3), which predicts three structural forms or zones as a function of T/Tm. where T is the substrate temperature and Tm is the coating-material melting point] have come into increased use in interpreting coating microstructures. There­ fore this review is organized from thc viewpoint of the zone models. After a brief survey of certain pertinent features of evaporation and sputtering, subsequent sections discuss each of the structural zones, metallurgical phase formation, and the mechanical properties of coatings. In this review the structure zones are defined in terms of dominant physical processes rather than structural forms. This generalization permits a broader correlation with experimental observations.

High Rate Thick Film Growth

Acknowledgements 1. Introduction 2. Electromagnetic wave propagation 3. The absorption of light 4. Specular reflection 5. Single particle scattering: perfect spheres 6. Single particle scattering: irregular particles 7. Propagation in a nonuniform medium: the equation of radiative transfer 8. The bidirectional reflectance of a semi-infinite medium 9. The opposition effect 10. A miscellany of bidirectional reflectances and related quantities 11. Integrated reflectances and planetary photometry 12. Photometric effects of large scale roughness 13. Polarization 14. Reflectance spectroscopy 15. Thermal emission and emittance spectroscopy 16. Simultaneous transport of energy by radiation and conduction Appendix A. A brief review of vector calculus Appendix B. Functions of a complex variable Appendix C. The wave equation in spherical coordinates Appendix D. Fraunhoffer diffraction by a circular hole Appendix E. Table of symbols Bibliography Index.

Theory of Reflectance and Emittance Spectroscopy

Large semiconductor crystals have intrinsic electronic properties dependent upon the bulk band structure. As the crystal becomes small, a new regime is entered in which the electronic properties (excited states, ionization potential, electron affinity) should be strongly dependent upon the electron and hole in a confined space. We address the possibility of a shift in the photochemical redox potential of one carrier, as a function of crystallite size. As a semiquantitative guide, one might expect a shift on the order of h2/8em*R2 due to the kinetic energy of localization in the small crystallite. We model the elementary quantum mechanics of a charged crystallite using (a) the effective mass approximation, (b) an electrostatic potential for dielectric polarization, and (c) penetration of the carrier outside the crystallite in a cases of small effective mass. Shifts of several tenths of an eV appear possible in crystallites of diameter 50 A. The carrier charge density reside near the crystallite surface if ...

A simple model for the ionization potential, electron affinity, and aqueous redox potentials of small semiconductor crystallites

The temperature‐dependent structure of crystalline methylammoniumtrihalogenoplumbates (II)—CH3NH+3PbX−3 (X=Cl, Br, I)—as determined by x‐ray diffraction, is compared with measurements of the temperature‐dependent complex permittivity at frequencies of 50–150 GHz. The dielectric measurements reveal a picosecond relaxation process which corresponds to a dynamic disorder of the methylammonium group in the high‐temperature phases of the trihalogenoplumbates.

David D. Yue

Papers

Theory of Electric Polarization

Fast Ion Transport in Solids, Solid State Batteries and Devices