Materials scientists

Demand for temperature controlled troughs came from the material scientists who worked witli large molecules and polymers tliat establish viscous films. Such troughs allow a deeper understanding of tire distinct phases and tire transitions in LB films and give more complete pressure-area isotlienns (see d) below). 

Tu K-N, Mayer J W and Feldman L C 1992 Electronic Thin Film Science for Electrical Engineers and Materials Scientists (New York Macmillan)... 

Transmission electron microscopy is very widely used by biologists as well as materials scientists. The advantage of being able to resolve 0.2 nm outweighs the disadvantages of TEM. The disadvantages include the inabiUty of the common 100-kV electron beam to penetrate more than a few tenths of a micrometer (a 1000-kV beam, rarely used, penetrates specimens about 10 times thicker). Specimen preparation for the TEM is difficult because of the... 

C. F. Zorowski and T. Murayama, Proceedings of 1 st International Conference on Mechanical Behavior of Materials, Vol. 5, Society of Material Scientists, Kyoto, Japan, 1972, p. 28. 

This book is primarily directed at professional materials scientists and engineers, and they have no urgent need to see themselves defined. Indeed, it would be perfectly reasonable to say about materials science what Aaron Katchalsky used to say about his new discipline, biophysics Biophysics is like my wife. I know her, but I cannot define her (Markl 1998). Nevertheless, in this preliminary canter through the early history of MSE, it is instructive to examine briefly how various eminent practitioners have perceived their changing domain. 

Later, in the 1890s, Arrhenius moved to quite different concerns, but it is intriguing that materials scientists today do not think of him in terms of the concept of ions (which are so familiar that few are concerned about who first thought up the concept), but rather venerate him for the Arrhenius equation for the rate of a chemical reaction (Arrhenius 1889), with its universally familiar exponential temperature dependence. That equation was in fact first proposed by van t HofT, but Arrhenius claimed that van t Hoff s derivation was not watertight and so it is now called after Arrhenius rather than van t Hoff" (who was in any case an almost pathologically modest and retiring man). 

Most materials scientists at an early stage in their university courses learn some elementary aspects of what is still miscalled strength of materials . This field incorporates elementary treatments of problems such as the elastic response of beams to continuous or localised loading, the distribution of torque across a shaft under torsion, or the elastic stresses in the components of a simple girder. Materials come into it only insofar as the specific elastic properties of a particular metal or timber determine the numerical values for some of the symbols in the algebraic treatment. This kind of simple theory is an example of continuum mechanics, and its derivation does not require any knowledge of the crystal structure or crystal properties of simple materials or of the microstructure of more complex materials. The specific aim is to design simple structures that will not exceed their elastic limit under load. 

Crystal structure, crystal defects and chemical reactions. Most chemical reactions of interest to materials scientists involve at least one reactant in the solid state examples inelude surfaee oxidation, internal oxidation, the photographie process, electrochemieal reaetions in the solid state. All of these are critieally dependent on crystal defects, point defects in particular, and the thermodynamics of these point defeets, especially in ionic compounds, are far more complex than they are in single-component metals. I have spaee only for a superficial overview. 

Australia, is the doyen of materials scientists who study the elastic and plastic properties of minerals under hydrostatic pressure and also phase stability under large shear stresses (Paterson 1973). J.-P. Poirier, in Paris, a professor of geophysics, was trained as a metallurgist one of his special skills is the use of analogue materials to help understand the behaviour of inaccessible high-pressure polymorphs, e.g., CaTi03 perovskite to stand in for (Mg, FelSiOi in the earth s mantle (Poirier 1988, Besson el al. 1996). 

The study of the multifarious magnetic properties of solids, followed in due course by the sophisticated control of those properties, has for a century been a central concern both of physicists and of materials scientists. The history of magnetism illustrates several features of modern materials science. 

Quite separate and distinct from this kind of science was the large body of research, both experimental and theoretical, which can be denoted by the term technical magnetism. Indeed, I think it is fair to say that no other major branch of materials science evinces so deep a split between its fundamental and technical branches. Perhaps it would be more accurate to say that the quantum- and statistical-mechanical aspects have become so ethereal that they are of no real concern even to sophisticated materials scientists, while most fundamental physicists (Neel is an exception) have little interest in the many technical issues their response is like Pauli s. 

Metallurgists originally, and now materials scientists (as well as solid-state chemists) have used erystallographic methods, certainly, for the determination of the structures of intermetallic compounds, but also for such subsidiary parepistemes as the study of the orientation relationships involved in phase transformations, and the study of preferred orientations, alias texture (statistically preferential alignment of the crystal axes of the individual grains in a polycrystalline assembly) however, those who pursue such concerns are not members of the aristocracy The study of texture both by X-ray diffraction and by computer simulation has become a huge sub-subsidiary field, very recently marked by the publication of a major book (Kocks el al. 1998). 

I have described Lifshin as a specialist in characterisation . This is almost a contradiction in terms, because the techniques that are sheltered under the characterisation umbrella are so numerous, varied and sophisticated that nobody can be truly expert in them all, even if his entire working time is devoted to the pursuit of characterisation. The problem is more serious for other materials scientists whose primary interest lies elsewhere. As Lifshin has expressed it in the preface to an encyclopedia of materials characterisation (Cahn and Lifshin 1993), scientists and engineers have enough difficulty in keeping up with advances in their own fields without having to be materials characterisation experts. However, it is essential to have enough basic understanding of currently used analytical methods to be able to interact effectively with such experts (my italics). ... 

The techniques, instrumentation and underlying theory of optical microscopy for materials scientists have been well surveyed by Telle and Petzow (1992). One of the last published surveys including metallographic techniques of all kinds, optical and electronic microscopy and also techniques such as microhardness testing, was a fine book by Phillips (1971). 

In the early years, physicists, metallurgists and chemists each formed their own community at Bell Labs, but the experience of collaboration in creating semiconductor devices progressively merged them and nowadays many of the laboratory s employees would rate themselves simply as materials scientists. 

The advent of the integrated circuit and its foundry has now firmly integrated materials scientists into modern electronics, their function both to optimise production processes and to resolve problems. To cite Just one example, many materials scientists have worked on the problem of clectronugraiion in the thin metallic conductors built into integrated circuits, a process which eventually leads to short circuits and circuit breakdown. At high current densities, migrating electrons in... 

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