bluuebunny/crossref_metadata_2025_split huggingface dataset:
The College-Wide Interdisciplinary Materials Science and Engineering Graduate Program
Authors: Bourell D.L. , Marcus H.L. 
Published: August 2016

The college-wide interdisciplinary graduate program approach to graduate education is a viable alternative to the departmental structure for areas of study that span two or more traditional disciplines. This article will explore the nature of this organizational style using materials science and engineering as the example discipline. We will discuss the advantages and disadvantages of the graduate program approach in the light of more than 18 years of experience at the University of Texas at Austin.The primary task of any center for higher learning is the education of students in an environment conducive to the open exchange and dissemination of ideas and knowledge. Traditionally, the university has approached this task by assembling scholars with common foundations of expertise into a collective group, the department. Besides the obvious function of providing a structured setting for the concentration of scholars with similar interests, the department also serves as the front line of faculty governance for matters including tenure, promotion, salary, resource management, and distribution. For example, course content and degree requirements are initiated at the department level. Thus the organizational structure of the college, and hence of the university, is firmly built on the traditional concept of department, a concept that has served education well.However, there are liabilities to the departmental structure since its natural tendency is to compartmentalize knowledge with the concomitant academic provincialism. This mindset poses a particularly serious problem for a number of subject areas that are intrinsically multidisciplinary. Several examples in the field of engineering science are biomedical engineering, manufacturing and industrial engineering, nuclear engineering, environmental engineering and also materials science and engineering.
New Materials and New Challenges in Vacuum Technology
Authors: Krauss Alan R. 
Published: August 2016

There are times when technological or scientific progress is blocked for want of a breakthrough in a key area, just as there appear to be instances of a problem and its solution emerging simultaneously and independently. Upon closer inspection, however, this latter happy state is usually the result of long, hard work by people who had the insight to develop a solution before their peers were aware of the existence of a problem. At the moment, there are a number of convergent events occurring in vacuum technology which in all likelihood will have as profound an effect as the development of ultrahigh vacuum (UHV) technology in the late 1960s and early 1970s. These developments may be viewed as challenges posed by the requirements of certain technologies, or as a series of breakthroughs which will lead to new opportunities. Materials and materials processing or coatings are the key factors in most of these new developments, just as new pump and seal designs, and new vacuum practice were responsible for the development of UHV (10−9–10−11 torr) technology.In particular, aluminum is emerging as a material which may replace stainless steel for applications where the ultimate in vacuum is required. By suitable treatment, pure aluminum and aluminum alloys can be made to produce static outgassing rates more than 10 times lower than stainless steel. Systems capable of reaching a base pressure in the extremely high vacuum (XHV) range of 10−12–10−13 torr, such as those described in this issue by H. Ishimaru, are now commercially available.
Coatings for Improved Vacuum Materials
Authors: Moriyama K. 
Published: August 2016

For the past 10 years, reactively deposited films of titanium nitride, TiN, have been applied to cutting tools such as drills, hob cutters, and endmills. A nominal film thickness of 2–4 μm has been shown to give excellent resistance to abrasion and corrosion and to extend tool life three times or more. This is attributable to the physical properties of TiN, which include microhardness of 1,800 kg/mm2 and surface friction approximately one-third that of high-speed tool steel. Corrosion resistance is realized from the dense, fine-grain equiaxed structure of the inert TiN film. Additional applications range from decorative use based on its goldlike appearance to use as a diffusion barrier in semiconductor devices.More recently, TiN has found application as a high quality coating for components used in ultrahigh vacuum (UHV and XHV) system apparatus and especially in high energy particle accelerators. This article discusses the application of TiN coatings to ultrahigh vacuum systems and high energy particle accelerators.The native oxides which form on stainless steel and aluminum tend to be porous and trap large amounts of water vapor and other gases. These trapped gases can be partially removed by vacuum baking, although for particle beam devices in which beam-induced desorption is at least as important as the thermal outgassing rate, an extensive beam-conditioning process is required to get rid of the final vestiges of trapped gas. The oxide surfaces have low sticking coefficients for the adsorption of incident gas molecules, but the oxides have much higher secondary electron yields than the clean metals and consequently have very high beam-induced desorption rates.
Vacuum Systems for Synchrotron Light Sources
Authors: Schuchman J.C. 
Published: August 2016

Synchrotron light sources are electron storage rings that produce synchrotron radiation by accelerating electrons in a circular storage ring. The synchrotron light (photon beam) is then used to irradiate various sample materials for basic and applied research in such fields as solid state physics, biology, chemistry, surface science, and technology.The electron storage ring must provide an ultrahigh vacuum environment for the electron beam to minimize electron residual gas collision which would shorten the beam-lifetime. This article will discuss the design of electron storage ring vacuum systems and materials, and how the choice of materials can affect the machine design.A typical electron storage ring is shown in Figure 1. It consists of an injector (linac and booster), transport system, storage rings, and experimental photon beam lines. These machines vary in size from a few meters in circumference for a compact light source used for x-ray lithography, to a few hundred meters in circumference for high energy physics.The vacuum system for an electron storage ring is an all-metal ultrahigh vacuum system. The operating pressure is in the low 10−9 torr range with stored electron beam, and 10−10 torr without beam.Certain unique vacuum problems must be faced in electron storage ring design: photon-stimulated gas desorption, power dissipation in the chamber walls, impedance changes due to changes in the chamber cross section, conductance limitations, accurate placement of the chamber, and all of those sundry problems associated with a large bake-able all-metal UHV system. Some of these characteristics are illustrated schematically in Figure 2. Two excellent papers that address many of these issues have been written by N. Mistry (system design) and H. Wiedemen (impedances and instabilities).
High Tc Oxide Superconductors
Authors: Maple M. Brian 
Published: August 2016

This issue of the MRS BULLETIN is devoted to high Tc superconductivity. It is the sequel to a previous series of articles on the same subject which appeared in the MRS BULLETIN in January 1989. While the articles in the January 1989 issue emphasized the families of high Tc superconducting oxides known at that rime, as well as novel processing techniques and thin films, the papers in this issue focus on the physical properties of high Tc oxide superconductors.The quality of polycrystalline and single-crystal bulk and thin-film materials has improved to the point where researchers can now make reliable measurements of many physical properties representative of the intrinsic behavior of these materials. As a result, a broad spectrum of important issues such as the nature of the electronic structure, the type of superconducting electron pairing, the magnitude and temperature dependence of the superconducting energy gap, the behavior of fluxoids in the vortex state, etc., can be addressed meaningfully. Presently emerging is a consistent picture of the physical properties of the high Tc oxides, which will form the foundation to eventually developing an appropriate theory for the normal and superconducting states of these remarkable materials.
Materials for Future High Performance Magnetic Recording Heads
Authors: Jagielinski Tomasz 
Published: August 2016

Recording in the 1990s will be high density, high frequency, in-contact recording on high coercivity media. Today's state-of-the-art head materials, NiFe, Sendust and amorphous alloys, will be used in some applications. However, layered structured and artificial superlattices will become the key head technologies of the future. Use of advanced preparation techniques will allow “true” materials engineering and the fabrication of devices to incredibly accurate specifications.These very high density recording systems will require optimal inter-play between all the components—media, head, and head/media interface. Future media will be very smooth, high coercivity, large moment thin films. The head/media spacing will be less than 50 nm, and recording at more than 100 MHz will be required. Single-track heads will be replaced by very narrow track-width multitrack devices in high data rate recorders. Thin film heads will provide the answer to most of the problems of large recording fields and high frequency response. These changes will define new requirements for head materials, some of which cannot be met by currently used materials. Conventional ferrite heads will not be found in high performance recording systems; thin film inductive and magnetoresistive (MR) heads (Figure 1) will be widely used. Thin films, metals and alloys, both crystalline and amorphous, layered structures and artificial superlattices will be the key head technologies in the future. New material preparation technologies, MBE (molecular beam epitaxy), MOCVD (molecular chemical vapor deposition), sputtering, and ion beam deposition are becoming increasingly available and less expensive. These methods will be used to fabricate future devices to incredibly accurate specifications.
Thin Film Recording Media
Authors: Judy Jack H. 
Published: August 2016

The rapidly growing demand for magnetic information storage systems at lower cost and higher capacity has driven the magnetic recording industry to accelerate development of thin film magnetic recording media. The ultimate recording density depends on the bit transition lengths, as shown in Figure 1 for various media, and on signal-to-noise ratio, which is proportional to the number of particles per bit. Longitudinal thin film media bit transition lengths are limited by thickness, magnetic properties, and zig-zag magnetic domain microstructures at the transitions, whereas in perpendicular media the principal limitation is the diameter of the grains. The recent development of quasi-particulate longitudinal and perpendicular thin film media indicates that areal bit densities substantially exceeding 109 bits/inch2 will be achieved in the future.This article will review magnetic phenomena relevant to thin film recording media, describe macromagnetic and micromagnetic characterization techniques, survey the development of state-of-the-art thin film media, correlate micromagnetics with magnetic properties, media noise, and recording performance, and discuss future requirements of longitudinal and perpendicular thin film recording media.Ferromagnetic and ferrimagnetic thin films exhibit a nonlinear, multivalued, and hysteretic relationship between the magnetic dipole moments per volume or magnetization M and the magnetizing field intensity H as shown in Figure 2 for the component of M in the direction of H.
Artificially Layered Superconductors
Authors: Schuller Ivan K. , Guimpel J. , Bruynseraede Y. 
Published: August 2016

The study of Artificially Layered Superconductors (ALS) started more than 20 years ago with the search for unusual and/or high temperature superconductivity in a variety of metal-semiconducting layers. Renewed interest was motivated by the advent of novel preparation techniques that allow control of layer thicknesses close to interatomic distances. In this way layered superconductors can be used as model systems to study a variety of physical phenomena, prepare structures with improved properties and discover novel metastable phases which do not exist in nature. Examples of these studies include: a diversity of dimensional transitions, interaction between superconductivity and magnetism, interaction between superconductivity and electron localization, enhancements of critical fields and critical currents, and the study of incommensurate systems.Recent developments in high temperature ceramic superconductors further increase the importance of studies of Artificially Layered Superconductors. The newly discovered ceramic superconductors are structurally layered and therefore many of their properties will also be determined by this structure. Because of this, particularly in the search for the mechanism of superconductivity, it is important to understand which properties are a consequence of the layered nature of the material and which are due to the presence of some unusual, yet undetermined physical phenomena.What makes Artificially Layered Superconductors especially attractive for investigation? The main reason rests on the fact that the characteristic lengths which determine the superconducting properties, i.e., the coherence length and penetration depth, are quite long in conventional low temperature superconductors.
Excimer Laser Drill for Multilayer Printed Circuit Boards: From Advanced Development to Factory Floor
Authors: Bachmann Friedrich 
Published: August 2016

A novel excimer laser process has been developed for generating cylindrical via holes with an aspect ratio of about one. The fabrication process is being successfully run on a production line for a highly miniaturized printed circuit board used for the multichip module in the new Siemens 7500 H 90 mainframe computer. The process is outstanding in terms of reliability and reproducibility. To the best of our knowledge, this is the first that that excimer lasers have been put into large-scale use in an industrial environment.Since signal delay times for chips have decreased much more rapidly than delay times for packaging, the computing speed of high-speed computers is restricted by the packaging techniques used. Therefore, further development of packaging technology became a prime objective for those developing high-performance computers. Packaging delay times had to be reduced drastically to keep up with increasingly shorter chip delay times. This, in effect, meant that a greater packaging density had to be implemented.A novel planar packaging technique has lead to considerable progress in solving this problem. This technique has been described in detail elsewhere. A key component in this technology is a multichip module, which can take in each of 16 areas, either an LSI module with 320 leads or 9 MSI modules with 52 leads as “bare” ICs. This means that a micro-wiring printed circuit board of this kind can accomodate between 16 (LSI) and 144 (MSI) chips. This article describes how these printed circuit boards are manufactured.As the specifications (Table I) show, blind vias 80 μm in diameter at a pitch of 0.5 mm have to be made in a 16-layer printed circuit board. It is intended that these blind vias will provide the through-contact for neighboring layers. The excimer laser plays a major role in this process.
Polymer Ionics
Authors: Ratner Mark A. , Shriver D.F. 
Published: August 2016

The preparation, utilization, and understanding of high polymers represents one of the great triumphs of chemistry and materials science in the 20th century. Synthetic polymers have traditionally been used as structural materials and electrical insulators. Biopolymers often exhibit interesting electrical response phenomena. A recent article in the MRS BULLETIN, for example, discussed piezoelectric properties of both synthetic and biopolymer systems. The newer, synthetic electroactive polymeric materials, however, represent one of the most exciting current areas of polymer materials science.Many synthetic ionic polymer materials are known; perhaps the first were the polyelectrolytes and crosslinked ion exchange materials. These are materials whose backbone contains charges of one sign, balanced by small counter ions of the opposite sign. Such polyelectrolytes have found very important applications in analytical chemistry, water purification, and chemical processing.Complexes, in which salts are dissolved in neutral polymer hosts, have until recently received less attention. The area of polymer/salt complexes became extremely active following the work of P.V. Wright, who first clearly showed that polyethylene oxide (PEO) is an excellent polymer host for a number of salts, and that the resulting solid polymer/salt complexes are electrical conductors. M. Armand broadened the investigation of electrical properties of polymer/salt complexes and pointed out that these materials might be useful in electrochemical devices, especially batteries.This article will discuss the formation, properties, behavior, and applications of polymer electrolytes and mixed conductors—that is, polymeric materials in which charge is transported either by ions or by ionic and electronic charge motion. Our concentration will be on solvent-free materials—materials in which no small molecule solvents are present. There is substantial interest, and substantial progress, in the area of solvent-swollen polymer electrolytes.
Using Analytical Electron Microscopy to Design Radiation Resistant Steels for Fusion Applications
Authors: Maziasz P.J. , Klueh R.L. , Rowcliffe A.F. 
Published: August 2016

The Fusion Reactor Materials Program in the United States began in about the mid-1970s, in a world sensitized to energy production needs by the 1973 Arab Oil Embargo. In the program's early stages, materials problems were recognized to be as important as any of the other problems facing this new energy technology. The effects of irradiation on the behavior of materials to be used in the first-wall and blanket structure were of particular concern. Today, although the economic and political realities that define energy needs have changed, fusion energy still remains an important part of our vision for a better future. Global environmental effects such as the “greenhouse effect” from increased CO2 in the atmosphere and acid rain, coupled with safety concerns about fission reactors, make fusion very attractive as a clean and safe energy source.Over the past 10 years, the range of candidate materials for structural application in fusion reactors has expanded to include new martensitic and ferritic steels with reduced activation characteristics, vanadium alloys, ceramics, and composite materials. However, because austenitic stainless steels are easily fabricated, nonmagnetic, reasonably strong and tough, commercially available, and familiar, they also remain as candidate materials for fusion. They have also been extensively studied for use in various fission reactor systems as well. The austenitic and stainless properties of Fe-Cr-Ni alloys and steels were discovered during 1900–1915. Commercial grades like AISI types 304 and 316 stainless steels were developed prior to World War II. The effects of irradiation on materials have been studied since 1942, when Eugene P. Wigner anticipated that fission fragments and energetic neutrons would damage crystalline materials by displacing atoms to create point defects (vacancies and interstitials).
Linus Pauling Addresses MRS in San Diego
Authors: Chianelli R.R. 
Published: August 2016

On Wednesday, April 26, 1989 at 6:00 p.m. Linus Carl Pauling, research professor, delivered the Plenary Address for the MRS Spring Meeting held in San Diego, California. He was introduced by John Baglin, Past President of MRS with the following words: “Linus Pauling…scientist, philosopher, and a thinker, whose fearless, pioneering research has made and continues to make vital and fundamental contributions to the sciences of chemistry, physics, mineralogy, biology and medicine. His work, frequently controversial, has stimulated thought and debate and research, promoting, indeed, the healthiest kind of scholarly activity within these many disciplines.”With these thoughts and many more in my head 1 set out for the airport the previous afternoon to pick up Linus Pauling. I was about to meet someone who had deeply affected my scientific career from my early days as an undergraduate through the most important and fundamental aspects of 15 years of research. I was aware of almost all of Pauling's prizes and awards, but I couldn't quite remember what he won his second Nobel Prize for (he won the Nobel Peace Prize in 1962 for presenting a petition to the Secretary-General of the United Nations to ban atom bomb tests), and it was while I was wondering about this that Linus Pauling walked toward me after exiting the airport security gate.
Surface Structural Techniques Applied to Interfaces
Authors: Robinson I.K. 
Published: August 2016

An interface is an internal surface, the boundary between two media which may be crystalline, amorphous solid, or liquid. Its close similarity with a surface, a solid-vacuum boundary, suggests that many of the powerful techniques available for studying surfaces might be applied to the interface structure problem. The extent to which this is possible is the subject of this article.The techniques to be discussed in this article include low energy electron diffraction (LEED), medium energy ion scattering (MEIS), x-ray diffraction, and x-ray reflectivity. (The most widely used method, transmission electron microscopy (TEM), is the subject of a separate article in this issue of the MRS BULLETIN.) To summarize what we will find, surface methods were developed to be nonpenetrating in order to have surface sensitivity. This works against us in the interface situation by requiring the use of extremely thin samples, at least on one side of the interface. This means special handling of samples in some cases and raises the possibility of artifac-tual results. Of the three methods, x-ray diffraction is the most penetrating and least surface sensitive; it probably has the greatest potential for widespread use in interface science.This article defines structure as “atomic structure” for this purpose: we are interested in the coordinates of atoms at the interface and their relation to bulk structures on one or both sides. For this reason, we will consider only interfaces that are crystalline on at least one side. Since crystals are by far our strongest structural reference point, much less can be said about other interfaces. We will also consider the morphology of an interface, defined as the boundary of the crystal(s) that demarcates the interface, also at the atomic level. This is most apparent in the form of interface roughness. The roles of strain and misfit dislocations in interface formation, also studied by these techniques, are outside the scope of this article.