Thermodynamic Properties of Solutions of Group IV Metals Dissolved in Liquid Sodium

Abstract

An emf cell technique was used to measure the thermodynamic properties of Pb-Na solutions at temperatures ranging from 245 ~ to 500~ and compositions between 2.35 and 16.79 atomic per cent (a/o) Pb. The results, while in general agreement with earlier work, reveal that the deviations from ideal solution behavior cross over from negative to positive at low Pb concentrations. This property has not been previously reported for the Pb-Na system. Sodium activity measurements, which were made as a function of decreasing temperature, display a marked change in slope upon transition to a two-phase region. The resulting liquidus-line is in agreement with the published phase diagram. A study of the change in sodium activity as a function of temperature was also made for saturated solutions of Ge in Na. The results show that the solubility of Ge in Na is represented by the equation

Thermodynamic Properties of Molten Sodium‐Lead Alloys: EMF Measurements and Interpretation

“…The agreement between the results derived from these cells and from the isothermal cells was within less than 2 at-% or a maximum of 2 mV. At the high-Na concentrations, our results are in excellent agreement with those of Hubberstey et al [12]. We have used their results to complement our data.…”

“…Except for XNa = 0.499, all of our emfs and those of Hubberstey et al [12] were very accurately represented by Eq. (13).…”

“…The variations of AS,,, agree in general with those reported by Matsunaga et al [li]; however, the small positive peak occurring at very high Na content was not detected in the earlier work. It should be noted that this region includes not only our measurements but also those of Hubberstey et al [12].…”

The use of solid electrolytes in the determination of activities and the development of sensors

“…In the presence of water vapor, [12] [ 13] In the presence of hydrogen, [14] As doped calcium zirconate is unstable in contact with aluminum, Iwahara used this electrolyte in the form of a tube surrounded by carbon felt, so that the aluminum was not in contact with the sensor but was able to equilibrate with the hydrogen in the aluminum. [20] Iwahara used, as a reference, a mixture of hydrogen in an inert gas, which necessitated the use of a gas cylinder, which is not always practicable in an industrial environment.…”

Thermodynamic properties of the Na–Bi–Pb system

“…One alloy system with the MNM transition are the Na-based alloys with Bi or Pb. The thermodynamic properties of the Na-Bi and Na-Pb binary alloys have recently been studied (1)(2)(3)(4)(5)(6). The ternary Na-Bi-Pb alloy for the eutectic solvent composition (XB, = 0.43) has also been studied (7), but the measurements were performed using a Na conducting glass electrolyte which is prone to degradation and uncertain measurements.…”