The hidden structure in liquid IIIB–VB alloys

Abstract The electrical resistivity, ρ, of liquid Ga–Sb and In–Sb alloys was measured by the dc four probe technique. The value of ρ remains metallic in character and the simple parabolic shape of the Nordheim rule is observed, in spite of the existence of intermetallic compounds with semiconductor properties at the 1:1 composition. However, the concentration dependence of the temperature dependence of ρ, dρ/dT, for these systems shows a minimum respectively at the eutectic compositions, which are present in the Sb-rich range for both systems. In the extreme case of Ga–Sb alloys dρ/dT is negative near the eutectic composition and the eutectic temperature, though ρ itself shows a metallic value of an order of 100 μ Ω cm. The existence of an anomaly only in dρ/dT implies that some hidden structure is present near the eutectic point in the respective liquid state. The anomalous behavior of ρ was successfully explained by the existence of concentration fluctuations, based on the effective medium theory, for which three kinds of domains exist. These are the domains of the semiconductor-like GaSb intermetallic compound, of the metallic-like Sb and of the metallic homogeneous liquid.