The following is an edited transcript of the plenary lecture presented by John P. McTague at the 1996 MRS Fall Meeting on December 2,1996 in Boston.

Long before 1993, the journey from New York City to San Francisco, across the continent, and from New York City to London, across the sea, will be made between the sunrise and sunset of a summer day. The railway and the steamship will be as obsolete as the stagecoach. And it will be as common for the citizen to call for his dirigible balloon as it now is for his buggy or his boots. Electricity will be the motive power, and aluminium or some lighter metal will be the material of the aerial cars, which will navigate the abyss of the sky.

John J. Ingalls

“Remarkable Changes in Everyday Life”(1893)

The following is an edited version of the Von Hippel Award address, given by recipient Sir Alan Cottrell at the 1996 MRS Fall Meeting. Cottrell received the Materials Research Society's highest honor for “converting crystal dislocations from a hand-waving hypothesis to a rigorous discipline, transforming the understanding of brittle fracture, making varied and crucial advances in the theory of radiation damage, and for transforming the teaching of materials science throughout the academic world through his pioneering textbooks.” Cottrell is an honorable distinguished research Fellow in the Department of Materials Science and Metallurgy, University of Cambridge.

The following is an edited version of the David Turnbull Lectureship address, given by recipient Robert E. Newnham at the 1996 MRS Fall Meeting. Newnham received the lectureship for “pioneering the field of ceramic composites for electronic and optical applications, and in recognition of a distinguished career of guiding students, lecturing, and writing.” Newnham is the Alcoa Professor of Solid State Science at The Pennsylvania State University.

The past decade has seen exciting advances in the discovery, improved synthesis and processing, and molecular level engineering of new inorganic materials having specialized electronic, ceramic, and structural applications. Many such materials share two common characteristics: They are complex in structure and composition (think for example of oxide superconductors), and they must be prepared by a series of steps under carefully controlled conditions (consider the intricacies of zeolite synthesis for example). The use of low-temperature aqueous synthesis conditions, with appropriate attention to pH, inorganic and organic structure-directing agents, and subsequent drying and calcination protocols has led to a wealth of new and often metastable crystalline polymorphs, to amorphous materials, and to fine powders with particles of nanoscale dimensions. Methods such as sol-gel synthesis, chimie douce (soft chemistry), hydrothermal synthesis, chemical vapor deposition, and various beam-deposition and epitaxy techniques produce a wealth of materials not constrained to be in chemical equilibrium with their surroundings and not representing the state of lowest free energy. Modern materials chemists almost have their pet Maxwell Demon to select atoms at will and cause them to assemble in a structure of controllable dimensions. The wealth of possible new structures formed begins to mimic the riches of organic chemistry. In this field, the fact that all complex organic and biochemical molecules are metastable under ambient conditions with respect to a mixture of carbon dioxide, water, and other simple gases is irrelevant except in a conflagration.

Liberation of ceramic science from the tyranny of high-temperature equilibrium is thus leading to new materials synthesized more quickly, at lower cost, and under environmentally more friendly conditions. There is of course a price to pay. First the synthetic procedures are more complex than traditional “mix, grind, fire, and repeat” ceramic processing. Second and more importantly, very little is known about the long-term stability of the materials formed, about their degradation during use, and about materials compatibility. Two examples of such problems are the potential corrosion of high Tc YBCO superconductors by ambient H2O and CO2, and the collapse to inactive phases of complex zeolitic and mesoporous catalysts under operating conditions. Chemical reactions in metastable materials are governed by an intertwined combination of thermodynamic driving forces and kinetic rates. For this rich landscape of new materials, neither the depths of the valleys nor the heights of the mountains are known. Often one cannot even tell which way is energetically downhill.

We humans have employed and improved materials for millennia, but it required the Industrial Revolution of the last century to birth the systematic, science-based development of materials. During this time, effort expended in understanding the process-microstructure-properties relationships of materials conferred great economic and military advantage upon the successful. The introduction of machine power in this era created great leverage for improvements in the strength, ductility, corrosion resistance, formability, and similar properties of materials. Response to this opportunity led to the emergence of the materials profession. Stimulated by opportunity, materials scientists and engineers of the day met many of the challenges by first understanding and then controlling the composition and microstructure of materials. In the process, they defined the materials-engineering profession and left their names as a part of its vocabulary: Martens(ite), Bain(ite), Austen(ite), Schmid, Bessemer, Charpy, and Jomminy, to name a few. In fact the understanding and control of microstructure is the hallmark of materials science and engineering. Of course the ancient art of finding, mining, concentrating, and refining materials from the earth's crust does not apply to this definition since we wish to focus on the engineering of materials.

Five decades ago, a new chapter in the evolution of this profession began by the invention of the transistor. This invention and the development of integrated circuitry that followed from it spawned a new era of materials achievement, again stimulated by the enormous economic and performance gains available. In this arena however, the object of the game was to completely eliminate microstructure while doing away with impurities, save for a desired few, to levels previously unimagined. Today a material thus prepared is a blank slate upon which we can write the microstructure of an integrated circuit.