H. Aoki et al., Anomalous behaviours of the electrical resistivity of the melt of a typical III-VGa-Sb system, J PHYS-COND, 11(50), 1999, pp. 10315-10322
The electrical resistivity, rho, was measured for the melt of a typical III
-V semiconductor system, Ga-Sb, by the direct-current four-probe method. Si
milarly to the case for solid substitutional alloys, the Nordheim rule almo
st establishes the concentration dependence of rho. That is. a rather parab
olic form of ap was obtained as a function of composition; Delta rho is the
deviation of the resistivity from the linear law relating the resistivitie
s of the pure components, liquid Ga and liquid Sb. In spite of this rather
simple behaviour of the concentration dependence of rho itself, its tempera
ture coefficient, d rho/dT, shows a clear minimum at the eutectic compositi
on and even a negative temperature coefficient was observed near the eutect
ic point. This negative d rho/dT may be the first indication for the existe
nce of particular hidden structure, related to concentration fluctuations,
in the liquid near the eutectic point. In addition, this strange behaviour
of d rho/dT was discussed on the basis of the effective-medium theory.