IONIC-CONDUCTIVITY OF LITHIUM NITRIDE DOPED WITH HYDROGEN

Lithium ionic conductivity of Li3N single crystals is reported for temperatures from 120 K to 350 K. The intrinsic ionic conductivity is rather small (< 10-6 Ω-1 cm-1 at 300 K) and shows no strong anisotropy. The activation energy is near 0,6 eV. It is shown that hydrogen is the critical impurity in the crystals grown and studied at this laboratory. The relative impurity concentration is determined from infrared transmission measurements near 3130 cm-1. An estimate for absolute values is obtained from dielectric studies. Increases in ionic conductivity with hydrogen doping by a factor 5000 are reported for E⊥c but no significant effects are found for E{norm of matrix}c. The proposed defect is an impurity-vacancy complex consisting of an NH-- and a lithium vacancy. © 1979.