bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interfaces Part I: Structure, Chemistry, Electronic Properties
Authors: Wolf Dieter , Yip Sidney 
Published: August 2016

Some of the most important properties of materials in high-technology applications are strongly influenced or even controlled by the presence of solid interfaces. For example, interfaces are the critical element in fiber-reinforced structural ceramics with mechanical properties not even imagined a decade or two ago. The entire electronics industry is based on the fascinating electrical properties of semiconductor interfaces, with ceramic-semiconductor, metal-semiconductor and metal-ceramic interfaces playing critical roles as well. Other examples are surface modification techniques, designed to enhance the corrosion resistance of materials in hostile environments or tailored for tribological or catalytic applications. In contrast to their enormous technological importance, our basic understanding of even the simplest interfaces, such as free surfaces and grain boundaries, is rudimentary at best. It is increasingly recognized, however, that truly significant technological advances can be achieved by a better understanding and control of interfacial processes.To draw attention to the tremendous opportunites that lie ahead in this lively area of materials research, some recent promising developments in the atomic-level understanding of solid interfaces are highlighted in this issue and in the October issue of the MRS BULLETIN. The theme common to ail the articles in the September and October issues lies in the atomic-level insights that have been gained. While this issue of the BULLETIN focuses on structure, chemistry and some electronic properties of crystalline interfaces, the October issue will be devoted to their mechanical and high-temperature behavior.
Up Close: Materials Science at the CSIRO Division of Applied Physics, Sydney, Australia
Authors: Window Brian 
Published: August 2016

The Division of Applied Physics of the Commonwealth Scientific and Industrial Research Organization performs research in the physical sciences to benefit Australian industry and also staffs the National Measurement Laboratory, underpinning the Australian measurement system. CSIRO is the major government-funded research organization in Australia, employing approximately 7,000 people, based in 30 divisions, and whose interests range from the agricultural and livestock areas through prospecting, mining, and manufacturing to information and communication technologies. The general mix of work in the divisions includes a proportion of basic science and a significant involvement in contract research with relevant Australian industries.The Division of Applied Physics is one of the oldest divisions and celebrates its 50th Jubilee in 1988. This year is also the 200th anniversary of European settlement in Australia and the 25th anniversary of the founding of the Australian Institute of Physics. It was a busy year for the laboratory!Materials science research in the Division developed from the needs of the standards research program, passed through a period of primarily basic research, and now concentrates on industrial research and the underlying basic research. Four areas which exemplify this progression toward applied research and development are described in this article.Thin film research started in the Division in the 1950s to produce optical coatings, driven by the requirements of a developing standards research program, and the needs of an astronomy program to study the surface of the sun spectroscopically.
Up Close: The Interuniversity Microelectronics Center (IMEC), Leuven, Belgium
Authors: Denoyelle Dirk 
Published: August 2016

The Interuniversity Microelectronics Center, Leuven, Belgium (IMEC) is one of the world's largest independent research centers for microelectronics. It was established in 1984 by the Flemish government as a part of a comprehensive program to promote high technology in Flanders, Belgium. Benefiting from existing experience available mainly at the University of Leuven, IMEC moved into its present facilities in 1986 (Figure 1).The Center covers a wide range of research topics in the microelectronics domain—VLSI systems design methodologies, advanced semiconductor processing, materials, packaging, and more.About 50 people work on computer-aided design, developing a series of “true” silicon compilers: CATHEDRAL. With this software, ASIC (application specific integrated circuit) design becomes extremely attractive, since CATHEDRAL covers design from the high system level down to layout.INVOMEC, the training division of IMEC, supports universities in ASIC design. It trains people for both educational institutes and industry in chip design, makes available the necessary software, and has a well-established Multi Project Chip—Multi Project Wafer service.The Processing Technologies and Materials Divisions involve about 200 people and have a 3,600 m2 clean room at their disposal. The clean room consists of a 20% class 10 area with a fast-turnaround prototyping line and an 80% class 1000 area.IMEC's objectives are: to perform research in the microelectronics field, supporting both industry and universities, and to stimulate the microelectronics industry in Flanders.IMEC performs research on both silicon and III-V technologies.
Microwear Analysis of Prehistoric Stone Tools
Authors: Berry Sarah H. , Bamforth Douglas B. 
Published: August 2016

Archaeologists have used microscopes to study traces of use on the edges of prehistoric stone tools for many years, but the past decade has seen a tremendous increase in the technical sophistication and substantive contributions made by this branch of archaeological research. Our purpose is to summarize the basic approaches archaeologists take to microwear analysis, the potentials of these approaches, and the kinds of traces that microwear analysts examine.Three forms of microwear analysis can be identified and are based on (1) the range of magnification, (2) the type of equipment, and (3) the type of traces examined. The first relies on stereoscopic microscopes, works at magnifications ranging from 10 to 75×, and examines patterns in the abrasion and chipping of tool edges during use. More recent research indicate s that important variation also exists in the way a tool surface is polished during use, and the second analytical approach examines differences in polish appearance as well as utilizing the techniques of the first method. Microwear polishes are visible at magnifications from 100× to 400× using binocular microscopes and incident illumination. Finally, the third approach relies on the scanning electron microscope (SEM) and very high magnifications to identify traces of materials on which the stone tools were used. In this discussion we emphasize the first two of these analytical approaches because very few analysts have used the SEM.
Organometallic Vapor Phase Epitaxy: Features, Problems, New Approaches
Authors: Ghandhi Sorab K. , Bhat Ishwara B. 
Published: August 2016

Modern compound semiconductor devices are usually fabricated in one or more layers of single-crystal material, which are epitaxially grown on a crystalline substrate. Since most of these semiconductors decompose into their constituent components at high temperature, epitaxial growth in its simplest form can be accomplished by transporting individual components to a heated substrate, where they react to form the compound semiconductor. This is the basis of molecular beam epitaxy (MBE), where the process is carried out in an ultrahigh vacuum environment.Growth of these materials in an atmospheric (or reduced pressure) environment is highly advantageous from a commercial point of view. However, this presents a problem, since one of the components usually has a very low vapor pressure. For III-V compounds such as GaAs, AlAs, InAs, and InP, this is the column III component. Consequently, a technique must be provided to transport these elements by means of volatile compounds. This process is known as chemical vapor epitaxy, with halogenic compounds often used as transport agents. One example of this approach is the growth of GaAs from GaCl and AsCl3. During growth, the AsCl3 is made to prereact with gallium to form volatile GaCl, which is stable at elevated temperatures and can be transported to the substrate. High quality GaAs can be made by this process, and it is widely used for making a number of GaAs devices.
Theoretical Modeling of Czochralski Crystal Growth
Authors: Derby Jeffrey J. 
Published: August 2016

The growth of single crystals with precisely controlled properties is one of the most demanding goals of modern materials processing, and its realization depends on the application of fundamentals from solid-state physics, chemistry, thermodynamics, and transport phenomena. Bulk semiconductor substrates and many high-power solid-state laser host materials are typically produced by solidification from the melt. The quality of the crystals produced this way hinges on process conditions which are predominantly determined by the transport of heat, mass, and momentum in the melt and crystal. Accurate modeling of melt crystal growth promises to enhance our understanding of existing systems and improve the design and control of future processes, thereby accelerating the development of advanced materials and devices.Theoretical modeling is often the only way to probe the complex interactions which characterize melt crystal growth, especially the effects of process changes on internal features of growth that cannot be directly measured on-line, such as the shape of the melt/crystal interface or temperature gradients within the growing crystal. In this way, computer simulation can serve as a design tool for developing control strategies and process innovations. Further, modeling serves as a test-bed for theoretical experiments which extend our knowledge of how fundamental physical phenomena govern the process.This report attempts to provide a glimpse of how analysis and modeling have impacted the understanding of Czochralski (CZ) crystal growth. The reader is referred to several excellent reviews for more in-depth information regarding melt crystal growth modeling.
Optical-Guided-Wave Modulators
Authors: Becker R.A. 
Published: August 2016

Planar optical-guided-wave devices have been in existence for over 20 years. Two interesting, informative articles can be found in References 1 and 2. Much of the early work in guided-wave optics was on passive devices, but this was also when much of the theoretical understanding of optical-guided-wave (OGW) devices was developed. This theoretical understanding applies to active devices as well. It's interesting to note that the commercialization of passive, glass-based guided-wave devices has just occurred with product introductions by Corning & Nippon Sheet Glass. Active OGW devices (i.e., ones where the light properties can be altered with an applied voltage) have been reported since about 1975. In 1985, Crystal Technology, Inc. announced the first commercially available product—a high-speed, efficient, intensity modulator. Throughout the ten years in between, a huge amount of technical literature has been generated. Most of the work has centered on the Ti:LiNbO3 waveguide technology although several other material systems have been demonstrated as well.Materials upon which optical-guided-wave modulators have been fabricated include: dielectrics such as lithium niobate (LiNbO3), lithium tantalate (LiTaO3), and potassium titanyl phosphate (KTP); the III-V semiconductor compounds, gallium arsenide (GaAs) and indium phosphide (InP); and a variety of organic polymers. Of these materials, waveguides on LiNbO3 are clearly the most developed and are offered for sale commercially. For this reason I will concentrate on this material system while making comparisons to the other material systems when appropriate.
Characterization of Materials by Thermoanalytical Techniques
Authors: Gallagher P.K. 
Published: August 2016

The generally accepted definition for thermal analysis is that it covers “a group of techniques in which a physical property for a substance and/or its reaction product(s) is measured as a function of temperature while the substance is subjected to a controlled temperature program.” From this broad scope, it is evident that at some point in their careers nearly all experimental materials scientists have been practicing thermal analysts. It is also obvious that the techniques of thermal analysis are applicable to the entire range of materials. Consequently, it is difficult, it not impossible, to properly review such a topic in several pages, but I hope that a carefully selected handful of examples will acquaint the readers with the standard techniques and the enormous versatility inherent in thermal methods. One aspect which simplifies the review is that the methods are conceptionally very simple and do not require extensive descriptions.Table I describes some of the more common techniques for which examples will be presented. Obviously, many more properties have been studied; however, those listed will suffice as an introduction to the subject.Because all information derived from thermal methods frequently has only an indirect correlation with the chemical concentration or process of interest, it is important to use more than one technique where possible.
Rapidly Solidified Neodymium-Iron-Boron Magnets
Authors: Croat J.J. , Herbst J.F. 
Published: August 2016

Permanent magnets have long occupied an important position in technology. Among the multitude of products using permanent magnets are televisions, telephones, computers, videocassette recorders, audio systems, household appliances, and perhaps surprisingly to many consumers, automobiles. Figure 1 illustrates the numerous magnet applications in a modern passenger vehicle. These applications include an array of dc electric motors such as the starter, heater and air conditioner blower, windshield wiper, window lift, door lock, and fuel pump motors. A fully equipped car can have more than 30 dc electric motors. Other uses include actuators, gauges, and sensors. In all these examples higher performance magnetic materials may afford the advantages of increased operating efficiency and reduction in size and weight.One performance index or figure of merit for a permanent magnet is the energy product (BH)max, the maximum product of magnetic induction B and applied field H in the second quadrant of the B-H hysteresis curve. The so-called theoretical (BH)max, the highest energy product realizable in principle, is simply given by (4πMs)2/4, where Ms is the saturation magnetization. Progress in the development of technologically significant hard magnets has been monitored generally by improvements in (BH)max. For many years three types of materials were of commercial importance, namely, alnico, ferrite, and samarium-cobalt alloys based on either the SmCo5 or Sm2Co17 intermetallic compounds. Of these the Sm-Co magnets offer the largest energy products, on the order of 20 MGOe.
Ultrasonic Characterization of Texture and Formability
Authors: Clark Alfred V. 
Published: August 2016

There are now theories which predict the effect of texture on elastic properties and hence on the velocities of bulk, surface, and guided ultrasonic waves. Furthermore, there is a relation between texture and formability. These relationships can be potentially exploited to make ultrasonic measurements of formability, and partial pole figures can be made with ultrasonic techniques.This article presents results of various ultrasonic measurements made to characterize the formability of rolled steel and aluminum alloy sheet. A good correlation generally exists between ultrasonic velocity measurements and formability. Furthermore, there is a good possibility of on-line formability measurement using a noncontacting ultrasonic transducer.The influence of texture on material properties has been long recognized, and several excellent texts have been wholly or partly devoted to the subject. Texture classically has been measured with either x-rays or neutron diffraction. Lately, there has been interest in characterizing texture with ultrasound (high-frequency sound) as well.Ultrasound has several potential advantages over x-ray and neutron diffraction techniques. Ultrasonic systems are nondestructive, can rapidly scan large volumes of material, require no radiation sources, and can be devised to measure either surface or bulk textures. There is a distinct possibility that ultrasonic texture monitoring can be implemented in real-time in a production environment such as a rolling mill.
Ultrasonic NDE for Surface Roughness
Authors: Eitzen D.G. , Blessing G.V. 
Published: August 2016

In a number of materials processes, on-line monitoring of surface finish is important to control material quality or process integrity. In rolling some sheet steel into coils, the rollers are intentionally roughened so that a specified roughness range is transferred to the sheet. Then the end product sheet can be optimally spray painted. The rollers, however, eventually wear smooth. Currently, pieces of sheet are sampled by hand and if a piece is too smooth, the coils produced since the last good sample are problematical. In automated machining it is useful to know during the cutting process whether the part will have the required surface finish. More importantly, for a large class of automated machining applications, a dull tool can be defined as one which produces a rougher part surface.Monitoring the finish of the newly cut surface could allow a decision to be made about changing the tool. For untended machining this could provide a strategy for tool management. The strategy would be much more efficient than the alternative of changing a tool after X hours when it might have lasted 10X hours were it in the upper 10% of the life curve.To fulfill the need for noncontact surface finish measurement, optical scattering devices have been developed to provide a surface interrogation technique. However, this technique is significantly limited for many applications because the optical beam must interact with a dry surface. This makes its application very difficult in the harsh wet environment encountered in automated machining and in some metal sheet production.
Preview: 1988 MRS Spring Meeting: Bally's ∎ Reno, Nevada Events Scheduled April 4-10
Authors: Clark David E. , Draper Clifton W. , Liu C.T. 
Published: August 2016

The 1988 Spring Meeting of the Materials Research Society will be held at Bally's in Reno, Nevada, with events spanning April 4-10. Program Chairs David Clark, Clif Draper, and Chain T. Liu have planned the most diversified topical symposia coverage to date. In addition to a thorough examination of the popular and “hot news” areas, the meeting will also offer a selection of intriguing specialty topics never before offered at an MRS meeting. This year's Spring meeting will feature 16 topical symposia, a program of 23 short courses, and an equipment show. Highlights of the symposia are described below. The names of the short courses and equipment exhibitors are listed elsewhere in this issue. For details see the 1988 MRS Spring Meeting Preliminary Program mailed to all MRS members.During the Plenary and Student Awards session, Raymond D. Tuminaro of AT&T Bell Laboratories will present the Plenary Address on “Materials Aspects of the SL Undersea Optical Cable Design.” Tuminaro will focus on the fiber and cable materials, review their vulnerabilities to degradation mechanisms, and explore methods currently being used to assure acceptable performance levels for the projected 25-year service life of these systems.A special feature is being planned for the 1988 MRS Spring Meeting. A major photomicrography exhibition—Microscapes: The Hidden Art of High Technology—will focus on the seldom-seen world of advanced developments in microelectronics and lightwave communications.
Up Close: Institut Max von Laue-Paul Langevin, An International Neutron Research Center
Authors: Maier Bernd P. 
Published: August 2016

The Institut Max von Laue-Paul Langevin (ILL) at Grenoble, France was formally founded in January 1967, with the signature of an intergovernmental convention between France and the Federal Republic of Germany. The aim was to provide the scientific community of the affiliated countries with a unique neutron beam facility applicable in fields such as the physics of condensed matter, chemistry, biology, nuclear physics, and materials science. The construction of the Institut and its high flux reactor was undertaken as a joint French-German project, with a total capital investment of 335 million French francs.The reactor first went critical in August 1971 and reached its full power of 57 MW for the first time in December 1971. The year 1972 saw the startup of the cold and hot sources, the first instruments, and the beginning of the experimental program.On January 1, 1973, the United Kingdom joined the Institut as a third equal partner, contributing its share to the total capital investment. In December 1986, an agreement on “Scientific Membership” for Spain was signed for a period of five years starting January 1, 1987. The ILL is a nontrading company under French civil law. The three countries are represented by the following associates: Kernforschungszentrum Karlsruhe GmbH (W. Germany), Centre National de la Recherche Scientifique (France), Commissariat
à l'Energie Atomique (France), and Science and Engineering Research Council (United Kingdom). These associates are represented on a Steering Committee which establishes the general rules of the management of the ILL.
Continuous Production of Narrow Size Distribution Sol-Gel Ceramic Powders
Authors: Ring Terry A. 
Published: August 2016

In the early 1980s Prof. Bowen at Massachusetts Institute of Technology advanced the concept that sintered ceramic bodies could be improved by decreasing the defects in green bodies. In addition, his group advanced the idea that ideal green bodies should be composed of monodisperse particles packed into an ordered array. They used the hydrolysis of metal alkoxides to produce narrow size distribution sol-gel powders (i.e., amorphous). These powders were allowed to settle under the force of gravity into an ordered array which was dried and sintered. Sintering took place at much lower temperatures and at faster rates than traditional ceramic processing (e.g., broad size distributions of crystalline powders). Improvements in strength and toughness of the sintered body were never demonstrated by Bowen's group for these novel ceramics.Ordered particles have packing faults which lead to ordered domains, as shown in Figure 1, similar to grains in polycrystalline materials. When sintered, the ordered domains shrink separately and pull away from each other as shown in Figure 2. This leads to defects in the sintered body of sizes similar to those of the ordered domains which can encompass as many as 10,000 particles. These ordered domains lead to weakness in the sintered body according to Griffith's theory.