The Computer as a Materials Science Benchmark

Abstract

When initially asked to prepare this Viewpoints piece on materials science, we selected the computer for the story line because of the breadth of materials it encompasses and its profound effect upon our lives. In no way, however, were we prepared for just how rapidly the materials and technologies associated with this remarkable tool are changing. During the four months over which this article was written-from our initial outline in August 1997 until the time it was completed in December 1997-it seemed that each time we developed a draft, a new technology was announced: IBM, for example, trumpeted a shift from aluminum to copper conductors in integrated circuits and introduced new magnetic read heads based on the giant magnetoresistance phenomenon during this period. Both of these advances will lead to faster, more powerful computers. Thus, writing this article has given us a distinctly unsettling but nonetheless exhilarating sense of how rapidly materials science is moving. We will not be surprised if, by the time you read this article, some of the materials and processes described will already have been outperformed and displaced, as suggested by the logarithmic plots that dot the landscape of this article. But what we hope will be conveyed is the breakneck pace at which this field is moving, and the vast potential and excitement it holds for all of us.

Replication and Compression of Surface Structures with Polydimethylsiloxane Elastomer

“…These patterned layers behave as a lithographic resist material for selective etching of the metal. This technique has been explored as an alternative to the lithographic techniques used in integrated circuit production (23).…”

An In-Depth Look at the Madelung Constant for Cubic Crystal Systems

“…Table 2 shows the same terms for the sodium chloride series as before with an extra column showing the net charge on the cluster of ions being considered. 2 It is evident that the charge varies greatly from the ideal value of 0, and it is this variance from neutrality that causes the calculated Madelung constant to be so erroneous and erratic. In fact, when the charge on the ion cluster approaches neutrality the calculated Madelung constant approaches the literature value of 1.74756.…”

“…Solid-state and structural chemistry need to become a more integral part of the undergraduate chemistry curriculum (1). The dearth of time and effort spent teaching solid-state chemistry is particularly noticeable because many of the most exciting recent scientific discoveries and applications pertain to solids and solid-state devices, from semiconductors to superconductors (2), from high-tech photonic devices to improved petroleum catalysts.…”

LEDs: New Lamps for Old and a Paradigm for Ongoing Curriculum Modernization

“…As these electrons relax to the ground state, energy corresponding to the difference in energy levels is emitted in a narrow band of wavelengths. The periodic properties that control the energy levels in the solid-atomic size and electronegativity-also control the wavelength of light emitted (2,(6)(7)(8)(9). Current LEDs have an expected lifetime of 100,000 h (5).…”

“…The development of the blue and green LED chips using GaInN technology, in conjunction with red chips based on AlGaInP technology (see below and Fig. 1), has permitted creation of red, green, and blue pixels that can be used for large-area, full-color video displays (9,17 ). Virtually the entire visible spectrum can be generated by independently varying the current supplied to each LED.…”