Elastic strain is a critical factor in engineering the electronic behavior of core-shell semiconductor nanowires and provides the driving force for undesirable surface roughening and defect formation. We demonstrate two independent strategies, chlorine surface passivation and growth of nanowires with low-energy sidewall facets, to avoid strain-induced surface roughening that promotes dislocatio...

The surfaces of strained mild steel sheet specimens were examined with scanning laser confocal microscopy. Rigorous assessments were employed to establish the form of the roughness data. The small deviations from the ideal conditions observed in these assessments indicated that the stochastic process responsible for surface roughening does not conform to stationary, Gaussian, Markov statistics....

Surface roughening during plasma enhanced chemical vapor deposition of hydrogenated amorphous silicon on crystal silicon substrates" Physical Review B. The morphology of a series of thin films of hydrogenated amorphous silicon ͑a-Si:H͒ grown by plasma-enhanced chemical-vapor deposition ͑PECVD͒ is studied using scanning tunneling microscopy. The substrates were atomically flat, oxide-free, single-cr...

Analogous to planar heteroepitaxy, misfit dislocation formation and stress-driven surface roughening can relax coherency strains in misfitting core-shell nanowires. The effects of coaxial dimensions on strain relaxation in aligned arrays of Ge-core/Si-shell nanowires are analyzed quantitatively by transmission electron microscopy and synchrotron X-ray diffraction. Relating these results to repo...

Three-dimensional (3D) aggregation of graphene is dramatically weak and brittle due primarily to the prevailing interlayer van der Waals interaction. In this report, motivated by recent success in synthesis monolayer amorphous carbon (MAC) sheets, we demonstrate that outstanding strength large plastic-like strain can be achieved layered 3D MAC composites. Both surface roughening ultracompliant ...

Fully-strained single-crystal metastable Ge12xSnx alloys were grown on Ge~001! up to their critical epitaxial thickness values tepi(x) in order to probe surface roughening pathways leading to heteroepitaxial breakdown during low-temperature molecular-beam epitaxy under large compressive strain. All films with x.0.09 have comparable roughnesses while films with x,0.09 are considerably rougher wi...

Hard-spin mean-field theory has recently been applied to Ising magnets, correctly yielding the absence and presence of an interface roughening transition respectively in d=2 and d=3 dimensions and producing the ordering-roughening phase diagram for isotropic and anisotropic systems. The approach has now been extended to the effects of quenched random pinning centers and missing bonds on the int...

Title of Document: PLASMA-SURFACE INTERACTIONS OF MODEL POLYMERS FOR ADVANCED PHOTORESIST SYSTEMS Sebastian Ulrich Engelmann, Doctor of Philosophy, 2008 Directed By: Professor Gottlieb S. Oehrlein, Department of Material Science and Engineering Plasma processing of advanced photoresist (PR) materials is a critical step in nano-manufacturing. We have studied the interactions of PRs and polymers ...

Introduction: One of the clinical problems in orthodontics is the bonding of brackets tocomposite restorations. The aim of this study was to evaluate the shear bondstrength of brackets bonded to composite restorations using Excite. Methods:Forty brackets were bonded to composite surfaces, which were embedded inacrylic resin. One of the following four protocols was employed for surfacepreparatio...