The reaction between barium and nitrogen in liquid sodium: resistivity studies

Abstract

The reaction of nitrogen with solutions of barium (between 0.34 and 6.89 mol % Ba) in liquid sodium at 573 K has been followed by changes in the electrical resistivity of the liquid. The capillary method has been employed, continuous sampling during reaction being achieved by electromagnetic pumping. The intial solution of nitrogen in the metal, followed by precipitation of barium and nitrogen from sodium as the nitride Ba₂N, are reflected in the resistivity changes. The solubility of nitrogen in the alloy is a linear function of the barium concentration: S(mol % N)=x/4 (0 ⩽x⩽ 6.89 mol % Ba). This, and the decrease in resistivity which invariably occurs during the solution process, provides additional information on the nature of solvation of nitrogen in solution in the liquid metal.