The role of fluctuations on the electrical resistivity and atomic volume for some liquid alloys with critical mixing

Abstract

The electrical resistivity, ϱ, was measured by the dc four probe method for some liquid alloys with critical mixing, that is Bi-Ga, Cd-Ga and Hg-Ga alloys. The maximum of temperature coefficient of ϱ, dϱ/dT, was found at the critical composition, X c , on the isotherm for liquid Bi-Ga and Cd-Ga alloys. This tendency becomes far striking at the critical temperature T c . However, an opposite minimum behavior of dϱ/dT was found at X c for liquid Hg-Ga alloys. The atomic volume, V M , was also measured by a picnometer method for liquid Bi-Ga alloys. The obtained V M is a linear function of composition. The value of thermal expansion coefficient, α p, near X c is large and shows a strong temperature dependence. The critical exponent β for liquid Bi-Ga alloys is determined to be 0.365 ± 0.02 in the range, 5.6 × 10 −5 ≤ ε(= ¦T T c¦/T c) ≤ 7.5 × 10 −2 from the binodal curve determined by resistivity measurements on heating with mixing by agitations.