Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Phd by thesis

Many materials systems are currently under consideration as potential replacements for SiO2 as the gate dielectric material for sub-0.1 μm complementary metal–oxide–semiconductor (CMOS) technology. A systematic consideration of the required properties of gate dielectrics indicates that the key guidelines for selecting an alternative gate dielectric are (a) permittivity, band gap, and band alignment to silicon, (b) thermodynamic stability, (c) film morphology, (d) interface quality, (e) compatibility with the current or expected materials to be used in processing for CMOS devices, (f) process compatibility, and (g) reliability. Many dielectrics appear favorable in some of these areas, but very few materials are promising with respect to all of these guidelines. A review of current work and literature in the area of alternate gate dielectrics is given. Based on reported results and fundamental considerations, the pseudobinary materials systems offer large flexibility and show the most promise toward success...

/pdf/high-k-gate-dielectrics-current-status-and-materials-zjvba0c4u8.pdf

High-κ gate dielectrics: Current status and materials properties considerations

Phase-change materials are some of the most promising materials for data-storage applications. They are already used in rewriteable optical data storage and offer great potential as an emerging non-volatile electronic memory. This review looks at the unique property combination that characterizes phase-change materials. The crystalline state often shows an octahedral-like atomic arrangement, frequently accompanied by pronounced lattice distortions and huge vacancy concentrations. This can be attributed to the chemical bonding in phase-change alloys, which is promoted by p-orbitals. From this insight, phase-change alloys with desired properties can be designed. This is demonstrated for the optical properties of phase-change alloys, in particular the contrast between the amorphous and crystalline states. The origin of the fast crystallization kinetics is also discussed.

Phase-change materials for rewriteable data storage

At interfaces between complex oxides, electronic systems with unusual electronic properties can be generated. We report on superconductivity in the electron gas formed at the interface between two insulating dielectric perovskite oxides, LaAlO3 and SrTiO3. The behavior of the electron gas is that of a two-dimensional superconductor, confined to a thin sheet at the interface. The superconducting transition temperature of ≅ 200 millikelvin provides a strict upper limit to the thickness of the superconducting layer of ≅ 10 nanometers.

/pdf/superconducting-interfaces-between-insulating-oxides-21qkm7ai8t.pdf

Superconducting Interfaces Between Insulating Oxides

Raman spectroscopy is a standard characterization technique for any carbon system. Here we review the Raman spectra of amorphous, nanostructured, diamond-like carbon and nanodiamond. We show how to use resonant Raman spectroscopy to determine structure and composition of carbon films with and without nitrogen. The measured spectra change with varying excitation energy. By visible and ultraviolet excitation measurements, the G peak dispersion can be derived and correlated with key parameters, such as density, sp(3) content, elastic constants and chemical composition. We then discuss the assignment of the peaks at 1150 and 1480 cm(-1) often observed in nanodiamond. We review the resonant Raman, isotope substitution and annealing experiments, which lead to the assignment of these peaks to trans-polyacetylene.

Raman spectroscopy of amorphous, nanostructured, diamond-like carbon, and nanodiamond

Thin homoepitaxial films of gallium phosphide (GaP) have been grown by remote plasma enhanced chemical vapor deposition utilizing in situ-generated phosphine precursors. The GaP forming reaction is kinetically controlled with an activation energy of 0.65 eV. The increase of the growth rate with increasing radio frequency (RF) power between 20 and 100 W is due to the combined effects of increasingly complete excitation and the spatial extension of the glow discharge toward the substrate; however, the saturation of the growth rate at even higher RF power indicates the saturation of the generation rate of phosphine precursors at this condition. Slight interdiffusion of P into Si and Si into GaP is indicated from GaP/Si heterostructures grown under similar conditions as the GaP homojunctions.

Remote plasma enhanced chemical vapor deposition of GaP with in situ generation of phosphine precursors

This paper presents experimental studies in which N-atoms have been incorporated at Si–SiO2 interfaces by forming the interface and oxide film by a 300°C remote plasma assisted nitridation/oxidation process using N2O. Process dynamics have been studied by on-line Auger electron spectroscopy (AES) by interrupted plasma processing. Based on AES studies using N2O, O2 and sequenced N2O and O2 source gases, reaction pathways for i) N-atom incorporation at and/or ii) removal from buried Si–SiO2 interfaces have been identified, and contrasted with reaction pathways for nitridation using conventional furnace processing.

Controlled Nitrogen Incorporation at Si-SiO2 Interfaces by Remote Plasma-Assisted Processing.

Transitions into, and out of intermediate phases (IPs) with minimal strain have been identified to date by Boolchand and co-workers, in bulk glasses, primarily by the extraordinary low values of the change in enthalpy, ΔHnr, associated with non-reversible heat flow, and by Lucovsky and coworkers in deposited thin films, and at dielectric–semiconductor interfaces by combining spectrographic characterizations, primarily synchrotron X-ray absorption and X-ray photoemission, and electrical measurements. This paper emphasizes chemical bonding self-organizations that minimize macroscopic strain within the IP windows, and identifies for the first time the necessary and sufficient conditions for IP windows to open, and to close, as a function of changes in the alloy composition. Percolation theory, and in particular competitive and synergistic double percolation provide a quantification of IP window first and second transition compositions that account for many of the experimentally determined IP window threshold transitions and IP window widths identified to date.

Strain-eliminating chemical bonding self-organizations within intermediate phase (IP) windows in chalcogenide, oxide and nitride non-crystalline bulk glasses and deposited thin film binary, ternary and quaternary alloys

The authors used x-ray absorption spectroscopy of the O K edge to investigate the nanocrystalline structure of thin HfO2 films deposited by remote plasma enhanced chemical vapor deposition on Ge(100). Postdeposition thermal process induced the interfacial reconstruction and the crystallization of the HfO2 in the monoclinic structure driven by the Ge(100) substrate. The substrate templating of the HfO2 crystallization is an evidence that the processing used here removes the undesired the interfacial layer and has the potential to yield interfaces with low density of defects.

Monoclinic textured HfO2 films on GeOxNy/Ge(100) stacks using interface reconstruction by controlled thermal processing

The white line and X-ray absorption near edge spectros-copy (XANES) spectral regions of the Ge K edge, ∼11100 to 11112 eV, and between 11112 and 11180 eV and beyond, contain electronic structure information that complements near-neighbor bonding information in the single-scattering EXAFS regime. The multiple-scattering XANES features are not generally addressed in EXAFS studies that are targeted to obtain bonding information. There are systematic changes in the X-ray photon energy of the spectral peak of the white line for Ge-Sb-Te (GST) alloys, GeSb and GeTe model compounds, and other Ge alloys that scale directly with average bond ionicity. The spectral widths of these features correspond tp electronic transitions important in optical memory devices. There are other features in the XANES region associated with shake-off effects for shallow atomic core states that re-veal bonding information important in analysis of the oscillatory features in the EXAFS regime. These include bonding pairs that are addressed in the fit procedures; e.g., Ge-Te and Ge-Sb in GST 225. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Gerald Lucovsky

Papers

Remote plasma enhanced chemical vapor deposition of GaP with in situ generation of phosphine precursors

Controlled Nitrogen Incorporation at Si-SiO2 Interfaces by Remote Plasma-Assisted Processing.

Strain-eliminating chemical bonding self-organizations within intermediate phase (IP) windows in chalcogenide, oxide and nitride non-crystalline bulk glasses and deposited thin film binary, ternary and quaternary alloys

Monoclinic textured HfO2 films on GeOxNy/Ge(100) stacks using interface reconstruction by controlled thermal processing

Analysis of the forgotten parts of the Ge K edge spectra: life before the EXAFS oscillations