Study of Formation of Solid Solutions of Lithium in Iridium

The interaction in the Li–Ir system using Li₃N as a lithium source was studied depending on the temperature, heat treatment time, and total pressure in the system. Using X-ray powder diffraction, it was shown that heat treatment of a powder mixture of Li₃N and Ir in a graphite or BN crucible in the temperature range of 800–1200°C leads to the formation of a substitution solid solution of Ir(Li), with the lithium content decreasing with increasing temperature, heat treatment time and decreasing total pressure in the system. The maximum lithium content in iridium reached 6.2 at %. It was shown that the use of a closed BN container increases the yield of the Ir(Li) solid solution. The use of graphite or BN crucibles prevents the formation of intermetallic compounds of the Li–Ir system.