Published online by Cambridge University Press: 25 February 2011
Using a planar thin-film specimen geometry, the growth kinetics of the spinel in NiOAl2O3 system has been studied with Rutherford backscattering spectroscopy. A thin-layer of Ni film is deposited by the electron-beam deposition technique onto single-crystal alumina substrates of different orientations including, (0001), {1120}, {1102} and {1100}. The subsequent heat-treatment in air then converts the Ni to NiO, thus producing a uniform layer of NiO with good adhesion between the NiO and the alumina. The kinetics of the Ni-Al spinel growth has been found to be different for different single-crystal substrate orientations. The kinetics behavior follows a parabolic growth-rate law for each orientation but shows a different reaction-rate constant. X-ray diffraction and transmission electron microscopy have been used as complementary techniques to confirm the phases that form at each stage of the heat treatment and the corresponding microstructures of the thin-film layers respectively.