The The recent discovery of superconductivity in FeAs-containing compounds (often known as the pnictides has provided a great stimulus to experiment and theory in the study of superconductors. The new materials are layered, as are the cuprate high-Tc superconductors, but the presence of Fe instead of Cu implies that more than one d-band is relevant to the superconductivity. We have recently used muSR very effectively to characterise the superconducting properties of some of these new compounds, including the new structure types LiFeAs and NaFeAs. This proposal is aimed at studying (i) the NaFeAs material, to try to understand the complex coexistence (or possibly competition) of magnetism and superconductivity for samples prepared in different ways and (ii) new compounds based on a more complex structural type.