Intermetallic compound ternary

The vast array of intermetallic compounds seems limitless, although it is finite. The number of binary compounds alone is in the thousands, and the number of ternary compounds is much larger. Still larger is the number of quaternaries, quin ternaries, and so on, ad infinitum. Not all of them are useful, of course, and there are many compounds having the same hardnesses as others. These overlapping cases are usually separated when other properties—such as corrosion resistance, toughness, or cost—are taken into account. 

Guenee et al. [169] synthesized by ingot metallurgy ternary intermetallic compounds LaNi Mg and NdNi Mg having the cubic MgCu Sn crystal structure. They can absorb reversibly up to four hydrogen atoms per formula unit at 7-8 bar and 50°C. The hydrides are stable at room temperature but desorb quite rapidly at 80°C in vacuum. In air, they decompose by catalytic water formation. 

Especially interesting are the metallic hydrides of intermetallic compounds, in the simplest case the ternary system because the variation of the elements allows... 

The rule of reversed stability is illustrated by Equation 15. When the stability of the intermetallic compound ABn is great, the stability of the ternary hydride is low therefore, the hydrogen dissociation pressure of the hydride is high (8). The rule of reversed stability aids in calculating approximate values... 

Betterton-KrollProcess. Metallic calcium and magnesium are added to the lead bullion in a melt and form ternary compounds that melt higher than lead and are lower in density. By cooling the lead bath to a temperature close to the melting point of lead, the intermetallic compounds high in bismuth content solidify and float to the top where they are removed by skimming. 

A. Szytula and J. Leciejewicz, Magnetic properties of ternary intermetallic compounds of the RT2X2 type 133... 

Figure 11.4.6 shows the pressure (P) versus composition (x) isotherms for the hydrogen-iron-titanium system. This system is an example of the formation of a ternary hydride from an intermetallic compound. 

Several crystalline ternary intermetallic compounds ate presently used in engineering applications. The ternary phase Ni2Mnln (Pearson symbol cF16) is illustrated in Figure 3.26a. Each atom is located on the site of a cesium-chloride cubic lattice. The unit cell consists of a FCC arrangement of nickel atoms with one additional nickel... 

Figure 5 Distribution of intermetallic compounds by crystal system (a) luiaries (elements), (b) binaries, (c) ternaries, and (d) quaternaries...

The first intermetallic compound that could reversibly absorb hydrogen (ZrNi) was reported by Libowitz et al. [60]. A magnesium-based hydride with relatively high capacity (Mg2Ni) was reported by Reilly and Wiswall in 1968 [61]. Later, room-temperature hydrides such as the ternary hydrides TiFeH2 and LaNisHfi were... 

In Ref. 11, the formulae for intermetallic compounds were also subject to an exceptional rule although no guidance was given for naming such compounds, and the term intermetallic compound was not defined. The problem is to define the term metal . Therefore, no attempt is now made to make a separate prescription for either the formulae or the names of intermetallic compounds. It is stressed, however, that the present recommendations allow some flexibility regarding formulae and compositional names of ternary, quaternary, etc. compounds. Several ordering principles are often equally acceptable (see Sections IR-4.4.2 and IR-4.4.3). 

Since the X-ray diffraction studies of Zintl et al. , these members of the family of intermetallic compounds have been of special interest because some of their chemical properties are unusual for intermetallic phases. Many experimental investigations have been reported for binary and ternary B32 type compounds. Besides the crystal structure " , the thermodynamic behavior , electrical conductivity ", magnetic susceptibility , NMR data elastic constants - and optical properties have been studied. Additionally for LiAl electrochemical investigations have been performed in view of the recent interest in fast ionic conductors " . ... 

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