Phase behaviour of 2D MnWO _x and FeWO _x ternary oxide layers on Pd(1 0 0)

The structure and properties of ternary oxide materials at the nanoscale are poorly explored both on experimental and theoretical levels. With this work we demonstrate the successful on-surface synthesis of two-dimensional (2D) ternary oxide, MnWO _x and FeWO _x , nanolayers on a Pd(1 0 0) surface and the understanding of their new structure and phase behaviour with the help of state-of-art surface structure and spectroscopy techniques. We find that the 2D MnWO _x and FeWO _x phases, prepared under identical thermodynamic conditions, exhibit similar structural properties, reflecting the similarity of the bulk MnWO₄ and FeWO₄ phases with the wolframite structure. Structure models of prototypical 2D ternary oxide phases are proposed and discussed in the light of new structure architecture concepts which have no analogues in the bulk.