Lithium ternary nitrides are emerging as promising candidates in several applications. They are currently a key focus in the search for improved anode materials in lithium ion cells. Iron and manganese based materials would offer a lower cost, lower toxicity alternative to Li2.6Co0.4N, and indeed Li2.7Fe0.3N has been shown to have comparable capacities. Our previous studies on nickel, cobalt and copper materials have shown that variation in synthesis conditions can have a large effect on vacancies in the structure, which in turn impact on Li ion conductivity. Higher metal doping levels have also been shown to lead to ordered phases such as LiNiN. The proposed experiment will extend these studies to the relatively unexplored iron and maganese doped nitrides and probe defect structure and vacancies in these promising new materials.