Metal aluminides

Behm J M and Morse M D 1994 Spectroscopy of]et-cooled AIMn and trends in the electronic structure of the 3d transition metal aluminides J. Chem. Rhys. 101 6500... 

Botton, G.A., Guo, G.Y., Temmerman, Szotek, Z., Humphreys, C.J., Wang, Y., Stocks, G.M., Nicholson, D.M.C., Shelton, W.A., 1996b, EELS studies of B2-type transition metal aluminides Experiments and theory, in Materials Theory, Simulations, and Parallel Algorithms, E. Kaxiras, J. Joannopoulos, P. Vashishta, R.K. Kalia, eds. Materials Research Society, Pittsburg, Vol. 408., 567. 

Figure 8.11 Hardnesses and heats of formation of some transition-metal aluminides. Data from E. R. Petty (1960).

In general, there are insufficient data available for quantitative estimates to be made of the hardnesses of intermetallic compounds. However, in some cases trends can be verified. Figure 8.11 illustrates one of these. It indicates that hardnesses and heats of formation tend to be related. In this case for a set of transition metal aluminides. The correlation in this case might have been improved if the heats per molecular volume couls have been plotted, but thr molecular volumes were not available. Nevertheless, the correlation is moderately good indicating that hardness and chemical bond strengths are related as in other compounds. 

Synthesis in liquidAl Al as a reactive solvent Several intermetallic alu-minides have been prepared from liquid aluminium very often the separation of the compounds may be achieved through the dissolution of Al which dissolves readily in several non-oxidizing acids (for instance HC1). For a review on the reactions carried out in liquid aluminium and on several compounds prepared, see Kanatzidis et al. (2005) binary compounds are listed (Re-Al, Co-Al, Ir-Al) as well as ternary phases (lanthanide and actinide-transition metal aluminides). Examples of quaternary compounds (alumino-silicides, alumino-germanides of lanthanides and transition metals) have also been described. As an example, a few preparative details of specific compounds are reported in the following. 

G. Fisher, W.Y. Chan, P.K. Datta, J.S. BumeU-Gray, Noble metal aluminide coatings for gas turbines, Platinum Met. Rev. 43 (1999) 59-61. 

Car] Carlsson, A.E., Meschter, P.J., Ab Initio Calculations of Stractural Energetics of Transitional-Metal Aluminides and Silicides , Mater. Res. Soc. Symp. Proc. High-Temp. Ordered Intermetallic Alloys IV, 213, 19-23 (1991) (Calculation, Thermodyn., 10)... 

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