Fast ionic conductivity in lithium nitride

Analysis of the frequency dependence of ac measurements with ionically-blocking electrodes, as well as transmission electron microscopic observations have enabled the transcrystalline and intercrystalline resistances of polycrystalline Li₃N to be separately evaluated. At 25°C the transcrystalline ionic conductivity is 6.6×10^?4 (ohm cm)^?1 and the activation enthalpy is 24.1 kJ/mole. The intercrystalline conductivity has an activation enthalpy of 68.5 kJ/mole, and its magnitude varies with thermal history. By optimized thermal treatment, the microstructure can be controlled so the bulk conductivity becomes approximately equal to that for transport in the fast direction in this very anisotropic structure.