The nature of the interaction layer formed at the Fe-(111) Au interface

Iron was vacuum deposited onto (111) gold platelets at substrate temperatures of approximately 300 °C. Diffraction spots which were not predicted by epitaxial relationships for iron-gold layers revealed the existence of a new phase in the Fe-(111) Au bicrystals. The structure of this new phase was positively identified as face-centred cubic by tilting diffraction experiments. The lattice parameter of the structure was determined and was found to be a function of the overgrowth thickness with a limiting value of $\text{3.875±0.001}\text{A}\text{?}$. The origin of the new phase is discussed and is indicated to be in the form of a thin interaction layer at the interface between the iron and the gold.