Magnetic Susceptibility of Molten Sodium–Sodium Chloride Solutions

The magnetic properties of dilute solutions of sodium metal in molten sodium chloride may be described by a free-electron gas model, whose spin degeneracy conforms to Fermi–Dirac statistics. Measurements are reported for the magnetic susceptibility in the temperature interval, 800–970°C, for solutions containing 0.00813–0.05347 mole fraction sodium. Correction of the observed susceptibility due to sodium and chloride ions leaves a residual paramagnetism which is ascribed to conduction electrons having rest mass and Landau diamagnetism. Exclusion of the cations and anions from the volume accessible to electrons leads to good agreement between the free-electron theory and experiment.