Crystalline solids alloy solid solutions

The crystallization of glassy Pd-Ni-P and Pd-Cu-P alloys is complicated by the formation of metastable crystalline phaf s [26]. The final (stable) crystallization product consists of a mixture of a (Pd,Ni) or (Pd,Cu) fee solid solution and more than one kind of metal phosphide of low crystallographic symmetry. Donovan et al. [27] used transmission electron microscopy (TEM) and X-ray microanalysis to study the microstructure of slowly cooled crystalline Pd4oNi4oP2o- They identified the compositions of the metal phosphides to be Pd34Ni45P2j and Pdg8Ni[4Pjg. 

Some of the major questions that semiconductor characterization techniques aim to address are the concentration and mobility of carriers and their level of compensation, the chemical nature and local structure of electrically-active dopants and their energy separations from the VB or CB, the existence of polytypes, the overall crystalline quality or perfection, the existence of stacking faults or dislocations, and the effects of annealing upon activation of electrically-active dopants. For semiconductor alloys, that are extensively used to tailor optoelectronic properties such as the wavelength of light emission, the question of whether the solid-solutions are ideal or exhibit preferential clustering of component atoms is important. The next... 

A further method of producing amorphous phases is by a strain-driven solid-state reaction (Blatter and von Allmen 1985, 1988, Blatter et al. 1987, Gfeller et al. 1988). It appears that solid solutions of some transition metal-(Ti,Nb) binary systems, which are only stable at high temperatures, can be made amorphous. This is done by first quenching an alloy to retain the high-temperature solid solution. The alloy is then annealed at low temperatures where the amorphous phase appears transiently during the decomposition of the metastable crystalline phase. The effect was explained by the stabilisation of the liquid phase due to the liquid—>glass... 

The second type of impurity, substitution of a lattice atom with an impurity atom, allows us to enter the world of alloys and intermetallics. Let us diverge slightly for a moment to discuss how control of substitutional impurities can lead to some useful materials, and then we will conclude our description of point defects. An alloy, by definition, is a metallic solid or liquid formed from an intimate combination of two or more elements. By intimate combination, we mean either a liquid or solid solution. In the instance where the solid is crystalline, some of the impurity atoms, usually defined as the minority constituent, occupy sites in the lattice that would normally be occupied by the majority constituent. Alloys need not be crystalline, however. If a liquid alloy is quenched rapidly enough, an amorphous metal can result. The solid material is still an alloy, since the elements are in intimate combination, but there is no crystalline order and hence no substitutional impurities. To aid in our description of substitutional impurities, we will limit the current description to crystalline alloys, but keep in mind that amorphous alloys exist as well. 

L. C. Correa da Silva and R.F. Mehl, Interface and marker movements in diffusion in solid solutions of metals, Trans. AIME, Vol. 191, pp. 155-173. Copyright by TMS (The Minerals, Metals, and Materials Society). Fig. 6.2 and Fig. 6.3 Reprinted, by permission, from A. Vignes and J.P. Sabatier, Ternary diffusion in Fe-Co-Ni alloys, Trans. AIME> Vol. 245, pp. 1795-1802. Copyright 1969 by TMS (The Minerals, Metals, and Materials Society). Fig. 6.2 Reprinted, by permission, from J.S. Kirkaldy, Diffusion in the Condensed State. Copyright 1987 The Institute of Metals (Maney Publishing). Fig. 9.1 Reprinted, by permission, from N.A. Gjostein, Short circuit diffusion, in Diffusion. Copyright 1973 by The American Society for Metals (ASM International). Fig. 9.2, Fig. B.6, and Fig. B.8 From Interfaces in Crystalline Materials by A.P. Sutton and R.W. Balluffi (1995). Reprinted by permission of Oxford University Press. Fig. 9.2 Reprinted, by permission, from I. Herbeuval and... 

Subject areas for the Series include solutions of electrolytes, liquid mixtures, chemical equilibria in solution, acid-base equilibria, vapour-liquid equilibria, liquid-liquid equilibria, solid-liquid equilibria, equilibria in analytical chemistry, dissolution of gases in liquids, dissolution and precipitation, solubility in cryogenic solvents, molten salt systems, solubility measurement techniques, solid solutions, reactions within the solid phase, ion transport reactions away from the interface (i.e. in homogeneous, bulk systems), liquid crystalline systems, solutions of macrocyclic compounds (including macrocyclic electrolytes), polymer systems, molecular dynamic simulations, structural chemistry of liquids and solutions, predictive techniques for properties of solutions, complex and multi-component solutions applications, of solution chemistry to materials and metallurgy (oxide solutions, alloys, mattes etc.), medical aspects of solubility, and environmental issues involving solution phenomena and homogeneous component phenomena. 

Peculiarity of the fullerene molecule formation also reveals itself in a fullerite crystal structure. Cubic crystal lattices of fullerites and hydrofullerites behave like those of different metals and alloys. Fullerene molecules are distributed in the lattice sites while atoms of elements are distributed in the octa- and tetrahedral interstitial sites forming the interstitial solid solutions. Fullerene molecules substitute each other in the sites of lattice and form the substitution solid solutions. Forming exo- and endocompounds, fullerene molecules that are in the lattice sites can change considerably the properties of crystal, whereas its crystalline structure remain unchanged. 

The various classes of metallic phases that may be encountered in crystalline alloys include substantially pure elements, solid solutions of one element in another and intermetallic compounds. In crystalline form, alloys are subject to the same type of defects as pure metals. Crystalline alloys may consist of a solid solution of one or more elements (solutes) in the major (base) component, or they may contain more than one phase. That is, adjacent grains may have slightly or extremely different compositions and be of identical or disparate crystallographic types. Often, there is one predominant phase, known as the matrix, and other secondary phases, called precipitates. The presence of these kinds of inhomogeneities often results in the alloy having radically different mechanical properties and chemical reactivities from the pure constituent elements. (Noel)5... 

An alloy is a metallic substance formed by melting together or otherwise mixing two or more elements, at least one of which is a metal. Many alloys are intermetallic compounds, with atoms of different elements in a well-defined ratio. Often the phase exists with a range of compositions. Such a phase may be called a solid solution or crystalline solution. 

Microstructurally, alloys are composed of alloy constituents that include alloy phases and, in some cases, unalloyed metals. Crystalline alloy phases can be subdivided into intermetallic phases, metal-nonmetal compounds such as borides or carbides see Borides Solid-state Chemistry Carbides Transition Metal Solid-state Chemistry), and terminal or complete solid solutions. 

A homogeneous crystalline material is not necessarily a pure substance. Thus natural crystals of sulfur are sometimes deep yellow or brown in color, instead of light yellow. They contain some selenium, distributed at random throughout the crystals in place of some of the sulfur, the crystals being fiomogeneous. and with faces as well formed as those for pure sulfur. These crystals are a crystalline solution (or solid solution). The gold-copper alloy used in jew elry is another example of a crystalline solution. It is a homogeneous material, but its composition is variable. 

Other words and expressions system, homogeneous, heterogeneous, phase, precipitate, filtrate, residue, supernatant liquid, centrifuge, supercentriiuge, emulsion, separatory funnel, still, condenser, receiver, distillate, gaseous solution, liquid solution, crystalline solution (solid solution), alloy, components. 

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