Composition-Dependent Electrical Resistivity in an Al-Re-Si 1/1-Cubic Approximant Phase: An Indication of Electron Confinement in Clusters

Abstract

We report the synthesis of alpha-AlReSi and show that it is a 1/1-cubic approximant phase of the icosahedral quasicrystal with a = 12.9 A. The trend of the resistivity of the new approximant phase shows a nonmetallic character, similar to those seen in the stable icosahedral phases. The resistivity depends sensitively on the Re concentration and the nonmetallic transport is observed only at the Re concentration close to 17.4 at. %, where the transition metal sites in the icosahedral cluster are exclusively occupied by Re atoms. In view of a recent ab initio calculation, the present result suggests strongly the formation of the virtual bound states, or confinement of electrons, in the icosahedral clusters of transition metal atoms.

Electronic transport in AlMn(Si) and AlCuFe quasicrystals: Breakdown of the semiclassical model

“…Experimental measurements show that approximant phases like α-AlMnSi [2], 1/1 AlCuFeSi [10], R-AlCuFe [2], 1/1 AlReSi [13,29] etc., have transport properties similar to those of quasicrystals AlPdMn and AlCuFe. This suggests that the local atomic order on the length scale of the unit cell, i.e.…”

Electronic transport of the icosahedral Zn–Mg–Sc quasicrystal and its 2/1 and 1/1 cubic approximants

“…On the other hand, qðT Þ of 1/1-Zn 85 Sc 15 exhibits a metallic character with a positive temperature coefficient; qðT Þ is rather linear with a small convex curvature at high temperatures and converges to a residual value at the lowest temperatures, a behavior that is reminiscent of that for normal metals. Such a metallic character was also seen in the Frank-Kasper-type approximants, such as 1/1-MgZn(Ga,Al) [8,9], 1/1-AlLiCu [10] and 1/1-CdYb [11], and is opposite to what was observed in the Mackay-type approximants, such as 1/1-AlMnSi [12], 1/1-AlCuFeSi [13] and 1/1-AlReSi [14]. In fact, qðT Þ of 1/1-Zn 85 Sc 15 agrees fairly well with the prediction of the Bloch-Gruneisen theory [15], supporting the argument that the electronic transport in 1/1-Zn 85 Sc 15 is essentially the same as that of normal metals.…”

Electrical resistivity of the Al65Rh27Si8 2/1 cubic approximant

“…With respect to electronic transport, such clusters are of particular interest for two reasons: (i) the transition metal atoms are considered to be strong scatterers for the conduction electrons, and (ii) icosahedral clusters composed of transition elements have a strong tendency to confine the electrons inside them, which is suggested by ab initio calculation [11] and also by experimental results [12].…”