Surface microsurgery is the science of preparing surface layers, such as oxide scales and coatings, for characterisation of their microstructure and composition, by conventional surface analytical techniques, such as SEM, EPMA, SIMS etc. A surface microsurgery procedure often employed involves the preparation of a taper section. Using relatively simple equipment, significant improvements have b...

The NRL developed tight-binding method has been very successful in describing the properties of nonmagnetic elemental metals and semiconductors with accuracy comparable to first-principles methods. In this article we discuss extensions of the method to magnetic systems. We first show that the method correctly predicts equilibrium ground state structures, elastic constants, and phonon frequencie...

The NRL developed tight-binding method has been very successful in describing the properties of nonmagnetic elemental metals and semiconductors with accuracy comparable to first-principles methods. In this article we discuss extensions of the method to magnetic systems. We first show that the method correctly predicts equilibrium ground state structures, elastic constants, and phonon frequencie...

Electron energy-loss spectroscopy (EELS) has become a standard tool for identification and sometimes also quantification of elements in materials science. This is important for understanding the chemical and/or structural composition of processed materials. In EELS, the background is often modelled using an inverse power-law function. Core-loss ionization edges are superimposed on top of the do...

Semiconductor photocatalysis has been intensively studied in recent decades for a wide variety of application such as hydrogen production from water splitting and water and air treatment. The majority of photocatalysts are, however, wide band-gap semiconductors which are active only under UV irradiation. In order to effectively utilize visible solar radiation, this thesis investigates various t...

nanoparticles classified in 4 overall groups containing: metallic nanoparticles, ceramic nanoparticles, polymeric nanoparticles and semiconductor nanoparticles. these nanoparticles are used in some biomedical applications such as carrying medicine and photographing agents. with attention to different criteria which are both qualitative and quantitative, selecting the most suitable nanoparticles...

At high pressure and temperature, the phase diagram of elemental carbon is poorly known. We present predictions of diamond and BC8 melting lines and their phase boundary in the solid phase, as obtained from first-principles calculations. Maxima are found in both melting lines, with a triple point located at approximately 850 GPa and approximately 7,400 K. Our results show that hot, compressed d...

Silicon nanowires will find applications in nanoscale electronics and optoelectronics both as active and passive components. Here, we demonstrate a low-temperature vapor–liquid–solid synthesis method that uses liquid-metal solvents with low solubility for silicon and other elemental semiconductor materials. This method eliminates the usual requirement of quantum-sized droplets in order to obtai...

Black phosphorus (bP) is the second known elemental allotrope with a layered crystal structure that can be mechanically exfoliated to atomic layer thickness. Unlike metallic graphite and semi-metallic graphene, bP is a semiconductor in both bulk and few-layer form. Here we fabricate bP-naked quantum wells in a back-gated field effect transistor geometry with bP thicknesses ranging from 6±1 nm t...