Alloying effect on the electronic structure of aluminium

Abstract

The influence of a number of alloying elements on the electronic structure of aluminium has been investigated by the DV-X, cluster method. The energy level structure was modified remarkably by alloying. For transition metals, for instance. this modification was mainly due to the appearance of the virtual bound state of d electrons near the Fermi energy level. Except for a few elements, the ionicities of alloying elements change monotonically following the electronegativity. The bond order between atoms largely depends on the alloying elements, while the activation energy for the 3d impurity diffusion in aluminium can be related to the calculated bond order. An increment of the residual resistivity, due to the 3d impurities doped into aluminium, also correlata well with the virtual bound stale densityat the Fermienergylevel. Inaddition, it isshown fromcalculations that Mn and Cr are probably the magnetic impurities in aluminium.

Tensile Properties of Bi Alloys and a Case Study for Alloy Design in Their Application to High Temperature Solders

“…2 and 3, it was associated with the electronegativity and the atomic radius of elements: namely, the Mk level decreased with increasing electronegativity of pure metals, whereas it increased with increasing the atomic radius, even though there were some differences in the correlations between transition metals and non-transition metals, which agreed with the relation obtained from the MAl 18 cluster as a model of fcc Al 22) . As explained in reference 23) , it was well known that the energy level obtained by the Xα calculation represented the electronegativity itself [24][25][26][27] . In addition, the p-orbital energy level may be employed instead of the s-orbital energy level, but the spherical symmetrical s-orbital was probably better for the estimation of the mechanical properties of alloys, compared with the directional p-orbital 28) .…”

Compositional Optimization of Al-Mn-X Alloys and, Their Tensile and Corrosion Properties

“…14) There was a good correlation between this weight loss and ¦Mk. As ¦Mk increased in alloys, this value decreased linearly, because ¦Mk value might have a certain correlation with the ionicity of M in MAl 18 cluster model, which agreed with the previous results, 14) although there were a few data.…”

“…It is well known that energy level obtained by the DV-X¡ cluster calculation represents the electronegativity itself. 14,15) There is also a liner relationship between Mk i level and the average level of all the s-orbitals of the element M existing in the MAl 18 cluster. In addition, the p-orbital energy level may be considered instead of the s-orbital energy level, but a spherical symmetrical s-orbital is probably better than a directional p-orbital for the purpose of investigating the mechanical properties of aluminum alloys.…”

Melting points and chemical bonding properties of 3d transition metal elements

“…The bond overlap population was derived from the DV-X orbitals in the calculations considering only the X exchange correlation, without electron correlation. Although the finer details with respect to energy are rather sensitive to the way electron correlation is included, information concerning the wave functions is insensitive to electron correlation and such DV-X calculations can be considered reliable [8][9][10][11][12]. Both the bond overlap populations and the melting points show the local minimal peak at manganese.…”