Keywords: Diamond Focused ion beam FIB EBSD EELS TEM STEM Ion implantation Amorphous carbon Diamond like carbonThe interaction between diamond and a 30 kV Ga + focused ion beam, has been studied. Electron backscattered diffraction identified the critical dose for amorphisation of the diamond surface at 2 × 10 14 Ga + /cm 2 . Scanning transmission electron microscopy identified a 35 nm amorphous carbon layer which, at higher doses, can swell up to 31% its original volume and accommodate a significant quantity of gallium. Electron energy loss and energy dispersive X-ray spectroscopy further characterised this layer and identified both excess hydrogen and oxygen contained within a stable amorphous carbon structure.

We present a study on the magnetization reversal in Co/Pt multilayer films with an out-of-plane easy axis of magnetization deposited onto substrates with densely distributed perforations with an average period as small as 34 nm. Deposition of magnetic Co/Pt multilayers onto the nanoperforated surface results in an array of magnetic nanodots surrounded by a continuous magnetic film. Following the evolution of the magnetic domain pattern in the system, we suggest that domain walls are pinned on structural inhomogeneities given by the underlying nanoperforated template. Furthermore, a series of micromagnetic simulations was performed in order to understand the modification of the pinning strength of domain walls due to the magnetic interaction between nanodots and the surrounding film. The results of the simulations show that magnetic exchange coupling between the nanodots and the surrounding film strongly influences the pinning behavior of the magnetic domain walls which can be optimized to provide maximal pinning.

The fabrication of free-standing GaN cantilevers on Si(111) is demonstrated, and the growth of III-nitride epilayers on silicon (111) using an AlN buffer layer is characterized. Mechanically releasing GaN structures from Si(111) required a combination of two dry inductively coupled plasma etch processes using Cl2/Ar and CF4/Ar/O2 chemistries, and a potassium hydroxide (KOH) aqueous etch. Scanning transmission electron microscopy reveals a columnar growth habit for the nitrides. Electron energy loss spectroscopy imaging of an AlGaN/GaN interface indicates columnar growth may strongly influence the potential piezoelectric properties of III-nitride cantilever microelectromechanical devices.

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