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

There is a special reason for reviewing this book at this time: it is the 50th edition of a compendium that is known and used frequently in most chemical and physical laboratories in many parts of the world. Surely, a publication that has been published for 56 years, withstanding the vagaries of science in this century, must have had something to offer. There is another reason: while the book is a standard fixture in most chemical and physical laboratories, including those in medical centers, it is not as frequently seen in the laboratories of physician's offices (those either in solo or group practice). I believe that the Handbook can be useful in those laboratories. One of the reasons, among others, is that the various basic items of information it offers may be helpful in new tests, either physical or chemical, which are continuously being published. The basic information may relate

Handbook of Chemistry and Physics

Transparent conductors as solar energy materials: A panoramic review

We report growth of one-dimensional semiconductor nanocrystals, nanowhiskers, in which segments of the whisker with different composition are formed, illustrated by InAs whiskers containing segments of InP. Our conditions for growth allow the formation of abrupt interfaces and heterostructure barriers of thickness from a few monolayers to 100s of nanometers, thus creating a one-dimensional landscape along which the electrons move. The crystalline perfection, the quality of the interfaces, and the variation in the lattice constant are demonstrated by high-resolution transmission electron microscopy, and the conduction band off-set of 0.6 eV is deduced from the current due to thermal excitation of electrons over an InP barrier.

One-dimensional steeplechase for electrons realized

Optical reflection, or in other words the loss of reflection, from a surface becomes increasingly crucial in determining the extent of the light-matter interaction. The simplest example of using an anti-reflecting (AR) surface is possibly the solar cell that incorporates an AR coating to harvest sunlight more effectively. Researchers have now found ways to mimic biological structures, such as moth eyes or cicada wings, which have been used for the AR purpose by nature herself. These nanoscopic biomimetic structures lend valuable clues in fabricating and designing gradient refractive index materials that are efficient AR structures. The reflectance from a selected sub-wavelength or gradient index structures have come down to below 1% in the visible region of the spectrum and efforts are on to achieve broader bands of such enhanced AR regime. In addition to the challenge of broader bands, the performance of AR structures is also limited by factors such as omnidirectional properties and polarization of incident light. This review presents selected state-of-the-art AR techniques, reported over the last half a century, and their guiding principles to predict a logical trend for future research in this field.

Anti-reflecting and photonic nanostructures

Variable angle spectroscopic ellipsometry (VASE) has been used in the photon energy range 125–50 eV to study the structure and optical properties of cerium dioxide (CeO2) films Both amorphous and highly oriented crystalline films were grown on sapphire by rf magnetron sputtering The crystallinity, chemical structure, and surface morphology of the films were studied by x‐ray diffraction, x‐ray photoelectron spectroscopy, and atomic force microscopy, respectively The measured VASE spectra on a series of films with different thicknesses were analyzed by using multiple optical models In this way, the complex refractive index N=n+ik of CeO2, the film thicknesses, and the surface roughness of the different films could be determined The ellipsometrically deduced refractive index spectrum was observed to be strongly dependent on the film structure Highly oriented crystalline CeO2 films exhibited a higher refractive index and a higher band gap energy than the amorphous film The surface roughness of the cr

A spectroscopic ellipsometry study of cerium dioxide thin films grown on sapphire by rf magnetron sputtering

Experimental and ab initio computational methods are employed to conclusively show that ScN is a semiconductor rather than a semimetal; i.e., there is a gap between the N $2p$ and the Sc $3d$ bands. Previous experimental investigators reported, in agreement with band structure calculations showing a band overlap of 0.2 eV, that ScN is a semimetal while others concluded that it is a semiconductor with a band gap larger than 2 eV. We have grown high quality, single crystalline ScN layers on MgO(001) and on TiN(001) buffer layers on MgO(001) by ultrahigh vacuum reactive magnetron sputter deposition. ScN optical properties were determined by transmission, reflection, and spectroscopic ellipsometry while in-situ x-ray and ultraviolet valence band photoelectron spectroscopy were used to determine the density of states (DOS) below the Fermi level. The measured DOS exhibits peaks at 3.8 and 5.2 eV stemming from the N $2p$ bands and at 15.3 eV due to the N $2s$ bands. The imaginary part of the measured dielectric function ${\ensuremath{\varepsilon}}_{2}$ consists of two primary features due to direct X- and \ensuremath{\Gamma}-point transitions at photon energies of 2.7 and 3.8 eV, respectively. For comparison, the ScN band structure was calculated using an ab initio Kohn--Sham approach which treats the exchange interactions exactly within density-functional theory. Calculated DOS and the complex dielectric function are in good agreement with our ScN valence-band photoelectron spectra and measured optical properties, respectively. We conclude, combining experimental and computational results, that ScN is a semiconductor with an indirect $\ensuremath{\Gamma}--X$ bandgap of $1.3\ifmmode\pm\else\textpm\fi{}0.3\mathrm{eV}$ and a direct X-point gap of $2.4\ifmmode\pm\else\textpm\fi{}0.3\mathrm{eV}.$

/pdf/electronic-structure-of-scn-determined-using-optical-2gevytcm52.pdf

Electronic structure of ScN determined using optical spectroscopy, photoemission, and ab initio calculations

One hundred years ago Michelson discovered circular polarization in reflection from beetles. Today a novel Mueller-matrix ellipsometry setup allows unprecedented detailed characterization of the be ...

/pdf/chirality-induced-polarization-effects-in-the-cuticle-of-2q1k7yv11k.pdf

Chirality-induced polarization effects in the cuticle of scarab beetles: 100 years after Michelson

2H–AlN(0001) layers have been grown on Si(111) by reactive magnetron sputtering from an Al target in Ar+N2 gas mixtures at temperatures Ts=400–900 °C. Variations in reactive gas consumption, target voltage, and current–voltage characteristics versus nitrogen partial pressure were used to determine deposition parameters required to yield stoichiometric AlN with growth rates ≥2 μm h−1. High‐resolution cross‐sectional transmission electron microscopy (XTEM) analyses of films grown at 900 °C showed that the initial 6–8 monolayers were (111)‐oriented cubic 3C before transforming to the (0001)‐oriented 2H polytype. The epitaxial relationship was found by XTEM and x‐ray diffraction (XRD) to be 2H–AlN(0001)//3C–AlN(111)//Si(111) with 2H–AlN[1210]//3C–AlN[110]//Si[110]. High‐resolution XRD ω−2Θ and ω rocking curve widths for films grown at Ts=900 °C were 70 and 500 arc sec, respectively, the lowest values yet reported.

Kenneth Järrendahl

Papers

A spectroscopic ellipsometry study of cerium dioxide thin films grown on sapphire by rf magnetron sputtering

Electronic structure of ScN determined using optical spectroscopy, photoemission, and ab initio calculations

Chirality-induced polarization effects in the cuticle of scarab beetles: 100 years after Michelson

Growth of epitaxial aln(0001) on si(111) by reactive magnetron sputter-deposition

Multiple sample analysis of spectroscopic ellipsometry data of semi-transparent films