Iron and Iron Nitride Layers on Wurtzite Gallium Nitride Studied Using MBE/STM

It is of interest to study epitaxial growth of iron and iron nitride (FeN) layers on wurtzite gallium nitride (w-GaN) as a possible magnetic/wide-gap semiconductor system for spintronics. X-ray diffraction (XRD) and reflection high energy electron diffraction (RHEED) of Fe deposited on GaN(0001) suggest the existence of the epitaxial relationship [110]$_{Fe}\vert \vert $ [0001]$_{GaN}$. Furthermore, multi-streak RHEED patterns indicate the formation of a multi-domain but smooth film. Also, we have investigated the growth of $\sim $ 1:1 iron nitride on w-GaN(0001) using nitrogen plasma-assisted molecular beam epitaxy (MBE). Both reciprocal and real space techniques were used to study the growth of FeN, including RHEED and scanning tunneling microscopy/spectroscopy (STM/STS). Bulk characterization was also applied, including XRD and transmission electron microscopy (TEM). The results indicate that zinc-blende FeN grows on GaN(0001) with the epitaxial relationship [111]$_{FeN }\vert \vert $ [0001]$_{GaN}$, and initial atomically-smooth FeN layers are formed. This work has been supported by DOE (Grant {\#}DE-FG02-06ER46317).