A structural study of electrodeposited Fe on n-GaAs(001)

The microstructure of Fe films electrodeposited onto n-GaAs(001) from FeCl2 and FeSO4-(NH4)(2)SO4 electrolytes was examined by X-ray and electron diffraction. Symmetrical theta-2 theta X-Ray diffraction from films deposited from chloride solutions indicates a dominant (001) texture with the presence of additional minority orientations. In contrast, deposition from an ammonium sulfate electrolyte yields films that only exhibit (001) scattering in the theta-2 theta geometry. Transmission electron microscopy (TEM) cross-sectional images of films grown in chloride solutions reveal intermittent cube-on-cube epitaxy that is also evident in plan view TEM dark field images. Interestingly, X-ray pole figure measurements for all specimens examined reveal an additional (221) orientation that is undetectable by symmetric theta-2 theta diffraction. The (221) oriented material most likely derives from twinning of (001) oriented grains during growth. (c) 2006 The Electrochemical Society.