Ionic conductivity in KCl-doped polycrystalline SrCl2

Conductivity studies on polycrystalline SrCl₂ doped with KCl have been carried out. The results are in substantial agreement with published results for single crystal work on SrCl₂, the activation energies being 1.8 eV for the intrinsic region, 0.35 eV for the extrinsic region, and 0.45 eV for the regions in which association of defects occurs. Most significant was the discovery of metastable electrolytes (4–5 mole% KCl in SrCl₂) having a conductivity of 1 × 10^?6 ohm^?1 cm^?1 at room temperature. These supersaturated solutions could be heat cycled up to 72°C, and they retained their initial conductivity after storage for 6 months at room temperature. This indicates that the equilibrium solubility of a dopant is not necessarily the limiting factor for extrinsic conductance in a solid material.