Surface morphology and chemical ordering in FePd/Pd(0 0 1) thin layers

The FePd alloy exhibits an L10 (CuAu-I type) chemically ordered phase which can be grown by molecular beam epitaxy at a low temperature (620 K) on Pd(0 0 1). The surface of the alloy has been observed by scanning tunnelling microscopy to determine the link between the surface morphology and the underlying chemical order. Steps are commonly observed with a bi-atomic height as a result of the surface processes leading to the chemical ordering. Mono-atomic steps are also observed and there is some evidence that they are linked to the antiphase boundaries between ordered domains within the growing layer.