bluuebunny/crossref_metadata_2025_split huggingface dataset:
Frontiers in β″-Alumina Research
Authors: Dunn Bruce , Farrington Gregory C. , Thomas John O. 
Published: August 2016

Beta and β″-alumina are remarkable solid electrolytes whose study has been a principal theme in the field of solid state ionics ever since Yao and Kummer first reported the exceptionally high conductivity of sodium β-alumina in 1967. The unusual properties of sodium β-alumina stimulated widespread interest in both the science and technology of high conductivity solid electrolytes. Since Yao and Kummer's seminal work, many solid electrolytes have been explored, but interest in the β and β″-aluminas has endured, principally because of their virtually unique ability to undergo ion exchange in which the sodium ions are replaced by a wide variety of monovalent, divalent, and trivalent cations as well as various protonic species. The β and β″-aluminas thus are not single compounds, but a family of solid electrolytes with diverse properties and potential technological applications.Kummer first pointed out the ion exchange properties of sodium β-alumina by showing that the sodium ions in the structure can be replaced by different monovalent cations, such as Li+, K+, as well as H(H2O)x+ and NH4+. More recent studies have shown that the ion exchange chemistry of sodium β″-alumina, is far richer than that of sodium β″-alumina. In fact, the sodium ion content of β″-alumina can be exchanged for virtually any +1, +2, or +3 cation in the periodic chart.
Mixed Conductors: Synthesis, Properties, Applications
Authors: Whittingham M. Stanley 
Published: August 2016

Only in the last two decades has the full realization been made that many materials can incorporate atoms or ions into their structures around room temperature. This incorporation frequently occurs with minimal structural changes so that the reaction can be reversed by appropriate chemical or electrical means. These materials include metals, inorganics, and organics. The driving force for reaction is a gain in free energy and is frequently associated with a transfer of electron density between the guest and host species. Thus by definition the host material must contain an electronic structure that can be readily oxidized or reduced, and hence for inorganic materials normally contains transition metals with their variable valences, or for organics a delocalized electron system.The systems described here frequently exhibit both electronic and ionic conductivity, i.e., they are mixed conductors over at least part of their composition range. They tend to have variable composition; this contrasts with solid electrolytes such as β-alumina which may also be nonstoichiometric but are of fixed composition at normal temperatures. Materials in this last category include the β-aluminas and aluminosilicates such as vermiculite and montmorillonite, both of which can be used as electrolytes due to their high ionic conductivity and low electronic conductivity.
Materials for Fusion Energy
Authors: Reuther Theodore C. 
Published: August 2016

Materials research and development specifically for potential application in fusion energy development had its origin in the early 1970s, following the impetus of the 1973 report to the President on “The Nation's Energy Future” by Dixie Lee Ray then chairman of the U.S. Atomic Energy Commission. The first scientific conferences on fusion materials took place in the summer and the fall of 1975 at Argonne National Laboratory and at Gatlinburg, Tennessee. Argonne's international conference set a direction for the use and development of irradiation testing facilities for fusion materials which continues today.In his keynote to the Gatlinburg meeting on “Radiation Damage and Tritium in Fusion Materials,” E.E. Kintner, then deputy director of the U.S. magnetic fusion program, spoke directly to the hearts of the materials community:“Materials is the Queen Technology of any advanced technical system. The economics eventually depend upon the materials, the reliability depends upon the materials, and the safety depends upon the materials. I assure you that before we are through with fusion, the physicists will give way to the materials engineers as being the leading lights of fusion.”Kintner spoke from his experience in naval and civilian nuclear power systems, with reference to the special threats of the fusion reactor environment to the integrity of materials, and from practical engineering issues in a broad sense.
Materials Requirements for Experimental Fusion Reactors
Authors: Smith Dale L. 
Published: August 2016

The next major step in the development of fusion power involves the design, construction, and operation of an experimental power reactor. The general objective of this type of device is to demonstrate key plasma physics, materials, and engineering performance under conditions that approach those considered necessary to establish the technical feasibility of fusion power. This device is generally perceived to be a tokamak configuration that operates on the deuterium-tritium (D-T) fuel cycle, which would produce several hundred megawatts of fusion power. Although a number of conceptual design studies on this type of device have been conducted, the current effort is focused on the International Thermonuclear Experimental Reactor (ITER) activity, a joint undertaking of the European Community (EC), Japan, the United States, and the Soviet Union, conducted under the auspices of the International Atomic Energy Agency (IAEA).The development of fusion power as an energy source depends to a large extent on the proper selection of materials for the various components. these materials will be exposed to a wide variety of conditions such as plasma particle and neutron radiation, high thermal fluxes, large thermal and mechanical stress, various chemical environments, and high magnetic fields. In order to achieve the high performance desired for a commercial power reactor, considerable materials development will be required. Because of the relatively near term time scale projected for ITER and the limited objectives, more conventional materials with more extensive data bases will be used where possible. Even so, a substantial materials development program is required to support a test reactor like ITER.
Participants Debate Cold Fusion During MRS Spring Meeting Panel Session
Authors: Siegel R.W. 
Published: August 2016

Capping an exciting day at the 1989 Spring Meeting of the Materials Research Society in San Diego, a special three-hour session on “cold fusion” was held Wednesday evening, April 26, following the plenary lecture by two-time Nobel laureate Prof. Linus Pauling. (See “Linus Pauling Addresses MRS in San Diego” elsewhere in this issue.)The session, the largest session in MRS history with over 1,700 participants, was sponsored by the Society to provide MRS meeting attendees with an unbiased scientific forum for the presentation and discussion of results and issues regarding recent “cold fusion” announcements in the press. The announcements had captivated the world's interest the preceding month while being met with a healthy amount of scientific skepticism. Such skepticism was not lost on the nation's cartoonists, many of whose works on “cold fusion” were shown during the evening's proceedings.The special session was organized and moderated by Meeting Cochair Richard W. Siegel, with the help of Angelica M. Stacy and Robin F.C. Farrow (also Meeting Co-chairs) and MRS President R.P.H. Chang. A distinguished panel of invited speakers from the nuclear fusion and materials research communities was assembled to discuss the purported fusion of deuterium nuclei dissolved in palladium or titanium at or near room temperatures.
The Basis and Needs for Intelligent Materials Processing
Authors: Apelian Diran 
Published: August 2016

The main concept of intelligent materials processing systems is to have online control during processing. Successful implementation of on-line control of materials processing from the total manufacturing point of view involves full integration of design, procurement, control of incoming components, manufacture, assembly, handling, packaging, and distribution.There are three primary concerns if on-line control of materials processing is to be successful:1. Definitive understanding of the process. Process models need to be developed which will bring forth an understanding of the processing variables.2. Sensors that can interrogate the processes in a manner that allows for process control. Sensing is needed throughout the processing steps so that one can determine and measure various indices and the significant parameters … as borne out by physical and mathematical modeling.3. Armed with the above, process controls are established to compare the on-line feedback obtained from sensors with the process models. When deviations are observed, measures are taken to change the processing variables so that the operation will yield a “quality” product. Intrinsic to process control is a clear definition of the properties required at the end of individual steps and the relation of the intermediate properties to those specified for the material when the total processing is completed. In fact, only in the light of a definition of the properties and the processes is it possible to define the parameters that can be monitored for on-line control.
Modeling of Defects in Silver Halides
Authors: Catlow C.R.A. 
Published: August 2016

Modeling methods are now established as a major technique in defect physics and chemistry. Indeed, much of the contemporary understanding of complex defect processes derives from applying these techniques in conjunction with experimental methods.The silver halides possess unusual defect properties and pose unique challenges to simulation studies. This article aims to outline the general features of defect simulations, and to review the status of their application to the defect properties of silver halides.Technical aspects of the field have been detailed elsewhere, so this account is brief. An important feature of recent studies of the silver halides concerns developments in interatomic potentials, which will be considered, followed by a presentation and discussion of the calculated defect parameters.The basis of the simulation techniques is the specification of an interatomic potential model for the system, i.e., an analytical or possibly a numerical description of the energy of the system as a function of atomic coordinates. For polar materials, the model must include the following terms: Coulomb and short-range energies, and ionic polarization.To evaluate these terms, charges must be assigned to all atoms. In most studies reported to date, the fully ionic model has been used, i.e., integral charges have been assigned. The procedure has been followed in modeling the silver halides. Care must be taken in summing r-1 terms. Simple truncation procedures give unreliable results.
Petrographic Analysis of Archaeological Ceramics
Authors: Childs S. Terry 
Published: August 2016

Petrographic analysis is not new to the study of archaeological ceramics, but it is receiving more attention as it is applied to interesting and diverse archaeological problems. Petrography was developed by geologists to identify minerals in rocks. Archaeologists use it to study the minerals that occur in prehistoric clay matrices transformed by heat to a rocklike state.Petrographic analysis requires a polarizing microscope and a piece of ceramic, called a thin section, 30 microns (0.03 mm) thick. As light from this specialized microscope passes through a mineral, it produces optical properties unique to that mineral. Birefringence and pleochroism are two such properties used to identify minerals, while physical properties such as cleavage and relief are also important discriminators. Several references fully explain these properties and relate them to specific minerals and rocks.Using petrographic techniques, as many as five materials can be studied in a ceramic—the clay itself, natural inclusions in the clay, purposefully added inclusions, and glazes or slips on the clay surface. Under certain conditions the clay or inclusions may melt and a fifth material, glass, may form. Depending on the research problem to be addressed and the samples available, the petrdgrapher studies one or more of these materials.
Characterization of Grass Phytoliths for Archaeological Analysis
Authors: Mulholland Susan C. , Rapp George 
Published: August 2016

The word phytolith means “plant rocks.” Phytoliths are mineral deposits that form in and between plant cells. Any mineral deposit may be considered a phytolith, although most recent research has focused on opaline silica. Silica seems to be widespread in at least some plant families and is resistant to dissolution in a pH less than 9. Silica phytoliths therefore have the potential to be useful microfossils that can be helpful in the documentation of prehistoric environment and economy.Identifiable shapes rather than amorphous deposits are a necessary characteristic for useful microfossils. Several plant families have long been known to be consistent accumulators of identifiable silica bodies: Gramineae (grass), Cyperaceae (sedge), and Equisetaceae (horsetail). Phytoliths from the Gramineae are especially well known; specialized silica-accumulating cells produce distinctively shaped phytoliths. However, other families have also been shown to produce significant amounts of identifiable phytoliths. Ulmaceae (elm), Fabaceae (bean), Cucurbitaceae (squash), and Compositae (sunflower) are a few examples of dicotyledonous families that commonly produce phytoliths. Some families, such as the Labiatae (mint), have yielded little or no identifiable phytoliths to date. However, further study may indicate phytolith production in particular species.
Arthur von Hippel: The Man Behind the Von Hippel Award
Authors: Dresselhaus M.S. 
Published: August 2016

The Von Hippel Award, the most prestigious award of the Materials Research Society was first presented to its namesake, Arthur von Hippel, in 1976. On November 19, 1988, Prof. von Hippel celebrated his 90th birthday, an appropriate occasion to look back on a lifetime of achievement. Through the many testimonials that were heard at his 90th birthday celebration from family, friends, former students and colleagues, emerged a picture of materials science that reflects much that we treasure as the fabric of the Materials Research Society, namely the interdisciplinary approach to materials research.It has become an annual tradition of MRS to celebrate the achievement of the Von Hippel Award winner, and each year the celebrants begin the ceremony with an affirmation of the efficacy of the interdisciplinary approach. In the early years of the Von Hippel Award, our young students often heard greetings from Prof. von Hippel himself during the opening ceremony. But as the size of the meetings has grown, it has become increasingly difficult for “The Professor” to offer personal greetings. Many young people today yearn for contact with their intellectual heritage. Inspired by this need, the leadership of MRS recommended that a brief article be written for the MRS BULLETIN on reminiscences about Prof. Arthur von Hippel and his legacy of the interdisciplinary approach to materials research.
Deposition Processes
Authors: Messier Russell 
Published: August 2016

My introduction in the November MRS BULLETIN to this two-part series on deposition processes discussed the extensive use of thin films in science and technology. That it takes two issues and nine articles to cover this topic — and by no means exhaustively — is testimony to the manifold ways thin films are prepared.If all deposition processes resulted in the same product, then such extensive coverage would be redundant and unnecessary. Thin films, however, cover a virtual infinity of free energy states — and related crystal structures, micro-structures, defects, defect densities, impurities, compositions, composition modulations, etc. — that are sensitive to the particular deposition process and its conditions. It is this richness of choice that makes thin film science and technology both exciting and, at times, frustrating.Along with the freedom to extensively vary thin film characteristics, resulting properties and applications comes the difficulty in understanding preparation-characterization-property relations in enough detail to control and reproduce deposition processes.The November articles covered molecular dynamics computer modeling of nucleation and growth processes, molecular beam epitaxy, organometallic vapor phase epitaxy, and chemical vapor deposition. This month's articles continue the sequence of ways to deposit films, the general direction being toward lower substrate temperatures. Plasmas, which offer both increased flexibility and complexity, are primarily considered. The last article covers thermal plasmas, not to control the vapor deposition but to melt powders which result in a multiple splat-quenched array of particles that form coatings important to industry.
Evaporation Processes
Authors: Bunshah R.F , Deshpandey C.V. 
Published: August 2016

Physical vapor deposition (PVD) technology consists of the basic techniques of evaporation deposition and sputter deposition. PVD is used to deposit films and coatings or self-supported shapes such as sheet, foil, tubing, etc. The thickness of the deposits can vary from angstroms to millimeters.Applications range widely, from decorative to utilitarian and over significant segments of the engineering, chemical, nuclear, microelectronics, and related industries. They have been increasing rapidly because modern high technology demands multiple and often conflicting sets of properties from engineering materials, e.g., combination of two or more of the following: high temperature strength, impact strength, specific optical, electrical or magnetic properties, wear resistance, fabricability into complex shapes, biocompatibility, cost, etc. A single or monolithic material cannot meet such demands. The solution is a composite material, a core material and a coating each having the requisite properties to meet the specifications.This article will review evaporation-based deposition technologies, theory and mechanisms, processes, deposition of various types of materials, and also the evolution of the microstructure and its relationship to the properties of the deposits.The first evaporated thin films were probably prepared by Faraday in 1857 when he exploded metal wires in a vacuum. The deposition of thin metal films in vacuum by Joule heating was discovered in 1887 by Nahrwold and was used by Kundt in 1888 to measure refractive indices of such films. In the ensuing period, the work was primarily of academic interest, concerned with optical phenomena associated with thin layer of metals, research into kinetics and diffusion of gases, and gas-metal reactions.
Plasma Spray Deposition Processes
Authors: Herman Herbert 
Published: August 2016

The concept of plasma is central to many scientific and engineering disciplines—from the design of neon advertisement lights to fusion physics. Plasmas vary from low density, slight states of ionization (outer space) to dense, thermal plasmas (for extractive metallurgy). And plasmas are prominent in a wide range of deposition processes — from nonthermal plasma-activated processes to thermal plasmas, which have features of flames and which can spray-deposit an enormous variety of materials. The latter technique, arc plasma spraying (or simply, plasma spraying) is evolving rapidly as a way to deposit thick films (>30 μm) and also freestanding forms.This article will review the technology of plasma spraying and how various scientific disciplines are contributing to both an understanding and improvement of this complex process.The plasma gun dates back to the 1950s, when it was introduced for the deposition of alloys and ceramics. Due to its high temperature flame it was quickly discovered that plasmas could be used for depositing refractory oxides as rocket nozzle liners or to fabricate missile nose cones. In the latter technique, the oxide (e.g., zirconia-based ceramics, spinel) was sprayed onto a mandrel and the deposited material was later removed as a free-standing form.The technique's versatility has attracted considerable industrial attention. Modern high performance machinery is commonly subjected to extremes of temperature and mechanical stress, to levels beyond the capabilities of present-day materials. It is becoming increasingly common to form coatings on such material surfaces to protect against high temperature corrosive media and to enhance mechanical wear and erosion resistance. Several thousand parts within an aircraft gas turbine engine have protective coatings, many of them plasma sprayed. In fact, plasma spraying has emerged as a major means to apply a wide range of materials on diverse substrates. The process can be readily carried out in air or in environmental chambers and requires very little substrate surface preparation. The rate of deposit buildup is rapid and the costs are sufficiently low to enable widening applications for an ever increasing variety of industries.
Magnetism in the High Tc Family of Compounds
Authors: Sinha Sunil K. 
Published: August 2016

The most intriguing aspect of the new “high Tc” superconductors is that we still have no consensus about the nature of the basic mechanism for superconductivity in these materials, nor about why Tc is so much larger than in conventional superconductors. As is now well known, these materials include compounds of the type La2-xSrxCu2O4-y (where Sr can also be replaced by Ba) in which the maximum Tc attained is between 35 K and 40 K, and of the type YBa2Cu3O7-δ (where Y can also be replaced by most rare-earth atoms) in which the maximum Tc attained is about 98 K. Very recently, new compounds such as Bi2Sr2CaCu2O8+y have been discovered where Tc's of up to 120 K have been observed, but the physical properties of these at the time of writing are much less well known. The interesting thing about all these compounds is that they all result from doping of cupric oxide insulators, and they all contain planes of Cu-O atoms.Perhaps not entirely by coincidence, high Tc superconductivity thus occurs in a class of materials, namely transition metal oxides, whose electronic ground states are currently least well understood in terms of conventional band theory. It is now generally accepted that the d-shells of transition metals ions (including Cu) have associated with them a fairly large Coulomb repulsion that makes it energetically unfavorable for two holes to be on the same d-shell simultaneously. For Cu, the energy U is estimated to be between 4 and 8 eV. This implies that Cu++ (d9 configuration) is favored, while Cu+++ (d8 configuration) is not. This is in accordance with spectroscopic measurements of these compounds.