Two-dimensional structures are an emerging class of materials within nitride chemistry. We report here our systematic studies of two groups of these layered compounds: 1 Lithium transition metal compounds, Li3-x-y□yMxN (M = Co, Ni, Cu, □ = Li vacancy) and 2 ternary transition metal nitrides of general formulation AMN2 (A = alkaline earth metal, M = Ti, Zr, Hf). Compounds in class 1 are based on the hexagonal Li3N structure, unique to nitrides. Compounds in group 2, by contrast, crystallise with oxide structures (α-NaFeO2 or KCoO2). Specific and unusual synthetic methods have been developed to reproducibly prepare these compounds. Compounds in series 1 contain ordered or disordered Li vacancies at increased levels relative to the parent Li3N, itself a Li+ fast ion conductor. Nitrides in series 2 should be nominally diamagnetic (S = 0), yet magnetic measurements reveal behaviour seemingly inconsistent with this assumption.
All Science Journal Classification (ASJC) codes
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys
- Materials Chemistry