Binary and ternary alloys

Go Binary and Ternary Alloyed Thin Films. Most of the thin-film media for longitudinal and perpendicular recording consist of Co—X—Y binary or ternary alloys. In most cases Co—Cr is used for perpendicular recording while for the high density longitudinal media Co—Cr—X is used X = Pt, Ta, Ni). For the latter it is essential to deposit this alloy on a Cr underlayer in order to obtain the necessary in-plane orientation. A second element combined with Co has important consequences for the Curie temperature (T ) of the alloy, at which the spontaneous magnetisation disappears. The for... 

The commercial production of silicon in the form of binary and ternary alloys began early in the twentieth century with the development of electric-arc and blast furnaces and the subsequent rise in iron (qv) and steel (qv) production (1). The most important and most widely used method for making silicon and silicon alloys is by the reduction of oxides or silicates using carbon (qv) in an electric arc furnace. Primary uses of silicon having a purity of greater than 98% ate in the chemical, aluminum, and electronics markets (for higher purity silicon, see Silicon AND SILICON ALLOYS, PURE SILICON). 

Shukla A, Neergat M, Parthasarathi B, Jayaram V, Hegde MS. 2001. An XPS study on binary and ternary alloys of transition metals with platinized carbon and its bearing upon oxygen electroreduction in direct methanol fuel cells. J Electroanal Chem 504 111-119. 

Statistical thermodynamic descriptions of these transitions in substitutional alloys have been developed for the cases of both binary and ternary alloys , using a simple nearest neighbor bond model of the surface segregation phenomenon (including strain energy effects). Results of the model have been evaluated here using model parameters appropriate for a Pb-5at%Bi-0.04at%Ni alloy for which experimental results will be provided below. However, the model can be applied in principle to the computation of equilibrium surface composition of any ternary solution. 

In summary, CO poisoning is held responsible for slow formic acid oxidation rates. Activity improvements should therefore correlate well with the CO tolerance of the catalytic surface. However, to date, no systematic study has been presented comparing the catalytic activity of different binary and ternary alloy surfaces under similar conditions for testing the model predictions of Figure 6.31. 

Binary and ternary alloys and oxides of these elements, as well as pure V, Nb, Gd, and Tc are referred to as Type II or high-field superconductors. In contrast to Type I, these materials exhibit conductive characteristics varying from normal metallic to superconductive, depending on the magnitude of the external magnetic field. It is noteworthy to point out that metals with the highest electrical conductivity (e.g., Cu, Au) do not naturally possess superconductivity. Although this behavior was first discovered in 1911 for supercooled liquid mercury, it was not until 1957 that a theory was developed for this phenomenon. 

Pulse metal deposition offers the possibility of producing alloy layers as well as multilayered systems. If, e.g., the metal ion discharge of the components of an alloy follows different Tafel characteristics, a defined alloy composition can be achieved by an appropriate potentiostatic pulse routine as shown for the deposition of brass, bronze, and other binary and ternary alloys within a wide compositional range. Furthermore, alloys with changing composition gradients, which are of high technical interest, can be produced. 

G.16 W. B. Pearson. A Handbook of Lattice Spacings and Structures of Metals and Alloys (New York Pergamon Press, 1958). A most useful source of information. Gives the crystal structures of intermediate phases, and the variation of lattice parameter with composition in solid solutions, of binary and ternary alloys. Also gives the crystal structures of metal borides, carbides, hydrides, nitrides, and binary oxides. 

The lead-free solders are mostly based on Sn-containing binary and ternary alloys. Among them, the Sn-Ag system is one of the earliest commercially available lead-free solders and has been recommended for general-purpose use as a substitute for Sn-Pb eutectic solder. Addition of nano-particles of second phase helps in improving thermo-mechanical properties such as melting temperature, mechanical strength, mechanical fatigue resistance, creep resistance and solder-joint reliability. 

Rh, Pt, etc. Plans are under way in this laboratory for studies of the static and dynamic structure of CO on binary and ternary alloys (e.g., ruthenium/platinum/tin) in methanol for fuel-cell applications. Such alloys display enhanced resistance to CO poisoning, and the nature of this resistance is appropriate for NMR investigation. For example, Pt-CO bonding information such as Pt-C connectivities, CO orientation and clustering, are accessible by Ti, T2, isotope dilution, and related techniques. In fact, essentially all of the techniques used in the past 20 years to study the solid-gas interface should now be applicable to NMR-electrochemistry, with the added bonus of potential control. 

Other approaches have focused upon using non-precious metals and their oxides as alternatives to the platinum catalysts. For example, the mixed oxide catalysts of the binary and ternary alloys of noble metals and transition metals have been investigated for the oxygen evolution reaction in solid polymer electrolyte water electrolyzers. Binary, ternary, and quaternary platinum alloys with base metals of Cu, Ni, and Co have been used as electrocatalysts in liquid acid electrolyte cells. It was also reported that a R-Cu-Cr alloy displayed better activity to oxygen reduction than R and Pt-Cr in liquid electrolyte.The enhanced electrocatalytic activity of these types of alloys has been attributed to various factors, including the decrease of the nearest neighbor distance of platinum,the formation of Raney type... 

Therefore, as for GdFe, and for the GdCoMo, GdCoCu and GdCoAu alloys, the origin of Ku is always unknown. The reader is referred to the results reported in each of the sections relative to these alloys in order to have a better idea of the complexity of the problem. Moreover the large discussion about as-deposited and annealed binary and ternary alloys given by Heiman et al. (1978) shows that a clear conclusion is not possible. Muller et al. (1979) notice that the temperature dependence of Ku is widely sensitive to the preparation conditions. They conclude, as Heiman et al. (1978), that more than one mechanism is responsible for the anisotropy. 

Sau] Saunders, N., Miodownik, A.P., Rangiha, J., Use of Vapour Co-Deposited Thin Films Containing Concentration Gradients in the Rapid Assessment of Phase Equilibria in Binary and Ternary Alloy Systems , J. Mater. Sci. Lett., 6, 1179-1181 (1987) (Crys. Sfrueture, Phase Relations, Experimental, Interface Phenomena,, 17)... 

Binary and ternary alloy powders are also possible to produce using this technique. Table 4 summarizes experimental conditions and the different alloys prepared using pulsed electrochemistry and sonication in Refs. [59-61]. 

The binary and ternary alloys are heterodesmic. In contrast to system n, a large proportion of the chemical bonds in system I is of the van der Waals type (because of the layered nature of the structure). 

The temperature curves of the thermal emf of binary and ternary alloys of copper with iron and cobalt were measured in the range of 2 to 300 K [1974Bei]. It was shown that the iron and cobalt contributions to the thermal emf are practically independent, which means that for the ternary alloys, it is essentially the superposition of the contributions from the binary alloys. This gives the possibility of determining the compositions of alloys for low temperature thermocouples with a given temperature dependence of the thermal emf. 

Table 9.2 Monolayer coverage calculations for binary and ternary alloys...

Braun F, Tarditi A, Miller JB, Comagha LM. Pd-based binary and ternary alloy membranes morphological and perm-selective characterization in the presence of H2S. J Membr Sci 2014 450 299-307. 

Pt-alloy catalysts, predominantly Pt binary and ternary alloys with 3D transition metals, have been the main focus of catalyst research for PEM fuel cells in the past decades, as they confer enhanced ORR activities over those available from pure Pt catalysts. Great progress has been made in past decades in developing more active and durable Pt alloy catalysts and in understanding the mechanism of... 

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