Structure, antiferromagnetism and superconductivity of the layered iron   arsenide NaFeAs
  A new layered iron arsenide NaFeAs isostructural with the superconducting lithium analogue, displays evidence for the coexistence of superconductivity and magnetic ordering. 
Dinah R. Parker, Michael J. Pitcher, Peter J Baker, Isabel Franke, Tom   Lancaster, Stephen J. Blundell and Simon J. Clarke