Properties of Intermetallic Compounds

Compounds of aluminum with transition elements attracts wide attention due to the need of high-performance structural materials in the aerospace, aircraft and automobile industries. The most promising candidates are compounds of aluminum with scandium, titanium, vanadium, and chromium. These transition metals have the outer electron shells 3d 4s, 3d 4s, 3d 4s, and 3d 4s respectively. Aluminum has the 3s 3p outer electron shell. The interatomic bonding in structures of trialuminides results from the overlap d-orbitals of transition metals with the hybridized sp orbital of aluminum. 

The authors of [27] underline Our present study of the elastic anisotropy represent only a first step towards an understanding of the origin of the brittleness of most TM trialuminides. 1 would like to add that the ultimate judgment may only be done by comparing with the experiment. 

Superconductivity is a phenomenon of exactly zero electrical resistance occurring in certain materials when cooled below some critical temperatures Tc- Superconductivity attracts attention of physicists and engineers because of prospects of its applications in industry. The matter is of research applications, defense and space, instruments for science and medicine, machine tools, materials processing, transportation, and energy. 

In a normal conductor, an electric current may be visualized as a fluid of electrons moving through a lattice ready-built of heavy ions. The electrons constantly collide with the ions in the lattice, and during each collision some part of the energy carried by the current is absorbed by the lattice. The energy of electrical current is converted into heat, which is essentially the vibrational kinetic energy of the crys- 

The situation is different in a superconductor. In a conventional superconductor, the electric current cannot be resolved into individual electrons. Instead, it consists of bound pairs of electrons known as Cooper pairs. The Cooper pairs are named for physicist Leon N. Cooper who, with John Bardeen and John Robert Schrieffer, formulated the first successful model explaining superconductivity in conventional superconductors. A key conceptual element in this theory is the pairing of electrons close to the Fermi level into pairs through interaction with the crystal lattice. 

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The valence theory of metals and intermetallic compounds is still in a rather unsatisfactory state. It is not yet possible to make predictions about the composition and properties of intermetallic compounds with even a small fraction of the assurance with which they can be made about organic compounds and 7— 553041. Lee brtx Nobel en /pjy. 

H.R. Kirchmayr and C.A. Poldy, Magnetic properties of intermetallic compounds of rare earth metals 55... 

D. Gignoux and D. Schmitt, Magnetic properties of intermetallic compounds 293 Author index 425... 

Table 1.3 Hydrogen storage properties of intermetallic compounds (from [12])...

Jacob, I. and Shaltiel, D., The Influence of A1 on the Hydrogen Sorption Properties of Intermetallic Compounds, "Hydrogen Energy Systems", Proc. 2nd World Hydrogen Energy Conf., 1978, Zurich, Pergamon Press, 3, 1689. 

J. H. Westbrook Mechanical Properties of Intermetallic Compounds - A Review of the literature. In J. H. Westbrook (eds.) Mechanical Properties of Intermetallic Compounds. J. Wiley, New York (1960) 1-70. 

Kirchmayr, H.R., and C.A. Poldy, 1979, Magnetic properties of intermetallic compounds of rare earth metals, in Handbook on the Physics and Chemistry of Rare Earths, Vol. 2, eds K.A. Gschneidner Jr andL. Eyring (North-Holland, Amsterdam) ch. 14, p. 55. 

Konenko, I.R., Starodubtseva, E.V., Fedorovskaya, E.A., Klabunovskii, E.I., Savitskii, E.M., and Mordovin, V.P. (1984) Sorption and catalytic properties of intermetallic compounds LaNi3,LaNi5 xCux and their hydrides, Izv. AN SSSR, Ser. khim. 754-758, Chem. Abstr. 1984, 101, 12769Z. 

Starodubtseva, E.V. (1990) Sorption and catalytic properties of intermetallic compounds in reaction hydrogenation of propylene and enantioselective hydrogenation of ethyl acetoacetate, Cand. Diss. Thesis, N.D. Zelinskii Institute of Organic Chemistry, Academy of Sciences of ihe USSR, Moscow (supervisors Klabimovskii, E.l. and Konenko, I.R.). 

We anticipated the need for other volumes to follow the first four, both to cover topics already mature but not included and others whose time had not yet come. We underestimated both aspects of this need. There is a time for a review of past work when the review itself promotes understanding and stimulates new lines of research. In response to this the publisher will continue the series to assure an evolving authoritative and comprehensive Handbook on the Physics and Chemistry of Rare Earths. Volume 5 contains new topics concerning thin films of alloys and compounds, transport properties of intermetallic compounds, catalytic behavior of metallic and non-metallic surfaces, defects and transformations in oxides, physical and chemical properties of fluorides, and spectroscopic properties of lanthanide ions in a variety of ionic hosts. 

The content of Chapter 9 sheds light on validity and application for different solids of the theory, which has been considered in previous chapters. The calculated values of cohesive energy and bulk modulus are compared with the experimental results. We present data on superconductivity, the embrittlement of metals, the electronic density of states, properties of intermetallic compounds, and the energy of vacancy formation. 

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