Silicon, binding energies Ei and IR absorption line energies of neutral thermal donors (TD0)

2005 ◽  
pp. 1-2
Author(s):  
Keyword(s):  
Absorption Line ◽  
Binding Energies ◽  
Ir Absorption

Foreign gas broadening of an IR absorption line of formaldehyde

2003 ◽  
Vol 217 (2) ◽  
pp. 153-156 ◽  
Author(s):  
M Burkart ◽  
B Schramm
Keyword(s):  
Absorption Line ◽  
Ir Absorption

Ab initio MO Calculations on the Structure and Raman and Infrared Spectra of [Al4O2Cl10]2– Oxide in Chloroaluminate Melts

2007 ◽  
Vol 62 (3-4) ◽  
pp. 157-168
Author(s):  
Rolf W. Berg
Keyword(s):  
Ab Initio ◽  
Vibrational Analysis ◽  
Binding Energies ◽  
Aluminium Chloride ◽  
Molecular Orbital Calculations ◽  
Oxide Content ◽  
Ir Absorption ◽  
Convergence Criteria ◽  
Model Calculations ◽  
Bonding System

The oxide complexation chemistry in molten tetrachloroaluminate salts and ionic liquids is discussed with respect to what possible structures may be formed in addition to [AlCl4]−: [Al2OCl6]2−, [Al3OCl8]−, [Al2O2Cl4]2−, [Al3O2Cl6]− and [Al4O2Cl10]2−. Ab initio molecular orbital calculations are carried out on these various aluminium chloride and oxochloride ions, in assumed isolated gaseous free ionic state, by use of the Gaussian 03W program at the restricted Hartree-Fock (HF) level and with the 6-31+G(d,p) basis set.Without any pre-assumed symmetries and with tight optimization convergence criteria and by using the modified GDIIS algorithm, the model calculations generally converge. The structures and their binding energies are presented. The expected geometries are supported, with one exception perhaps being the [Al2OCl6]2− ion, that gave a linear Al-O-Al bonding system of staggered AlCl3-groups (approximate D3d symmetry), in analogy to the linear Al-O-Al geometry of the analogous [Al2OF6]2− ion, found previously. The calculations include determination of the vibrational harmonic normal modes and the infrared and Raman spectra (vibrational band wavenumbers and intensities), without any empiric adjustments of the harmonic force constants, using constants directly predicted from the Gaussian 03W program. Previously obtained IR absorption and Raman scattering spectra of melts are assigned, by comparing to the ab initio quantum mechanical vibrational analysis results. It is concluded that the small oxide content commonly found in basic and neutral tetrachloroaluminate melts, most probably consists of [Al4O2Cl10]2− ions, and the vibrational spectra are given.

Biophysical Analyses of Sequential Bands of Enamel Related to Ruffle-ended and Smooth-ended Maturation Ameloblasts

1989 ◽  
Vol 68 (2) ◽  
pp. 101-106 ◽  
Author(s):  
M.D. McKee ◽  
J.R. Martin ◽  
W.J. Landis
Keyword(s):  
Photoelectron Spectroscopy ◽  
Alveolar Bone ◽  
Matrix Effects ◽  
Binding Energies ◽  
Enamel Organ ◽  
Tooth Surface ◽  
Ir Absorption ◽  
Absorption Bands ◽  
Ether Anesthesia ◽  
X Ray

During amelogenesis in the rat incisor, modulating ruffle-ended (RA) and smooth-ended (SA) ameloblasts are distributed as bands in the enamel organ of the maturation zone. This distribution of the two cell types has been shown to be precisely correlated with a banding of the underlying enamel, as shown by staining and other cyclical indicators (Takano et aL, 1982a,b). Several biophysical approaches have been taken here to characterize the enamel bands sequentially and to determine whether the appearance of such bands is attributable to differences in inorganic composition possibly related to RA and SA. Sprague-Dawley rats were decapitated under ether anesthesia, lower incisors were dissected from surrounding alveolar bone, and enamel organs were wiped from the teeth with moistened gauze. Analyses were performed on either the surface of intact enamel or on individual strips of enamel dissected from the tooth surface, by use of the translucent bands that appear during drying as reference marks for the positions of the overlying cell type. X-ray diffraction (XRD), infrared spectroscopy (IR), x-ray photoelectron spectroscopy (XPS), and wavelength-dispersive electron probe x-ray micro-analysis (WDS) all failed to detect significant differences between analysis areas; data were characteristic of enamel apatite having typical XRD maxima (hkl = 002, 211, 112, 300), IR absorption bands (PO43- and CO32-), XPS Ca and P binding energies (Ca2p = 350.5, 346.9 eV; P2p = 133.7, 132.7 eV), and WDS Ca/P molar ratios (1.33 - 1. 49). It is concluded that discernible differences in Ca and P chemistry in enamel related to RA and SA are extremely small, and that enamel banding may not be solely an intrinsic property of changes in the inorganic component of this tissue but may also be a function of organic matrix effects determined by cumulative cellular modulations during enamel maturation.

Plasmon-assisted interaction of Si with light, for cancer hyperthermia and electromagnetic energy harvest

2020 ◽  
Vol 92 (2) ◽  
pp. 20101
Author(s):  
Behnam Kheyraddini Mousavi ◽  
Morteza Rezaei Talarposhti ◽  
Farshid Karbassian ◽  
Arash Kheyraddini Mousavi
Keyword(s):  
Silicon Nanowires ◽  
Metallic Nanoparticles ◽  
Near Infrared ◽  
Optical Transition ◽  
Electromagnetic Energy ◽  
Energy Harvest ◽  
Absorption Enhancement ◽  
Ir Absorption ◽  
Absorption Mechanism ◽  
Near Ir

Metal-assisted chemical etching (MACE) is applied for fabrication of silicon nanowires (SiNWs). We have shown the effect of amorphous sheath of SiNWs by treating the nanowires with SF6 and the resulting reduction of absorption bandwidth, i.e. making SiNWs semi-transparent in near-infrared (IR). For the first time, by treating the fabricated SiNWs with copper containing HF∕H2O2∕H2O solution, we have generated crystalline nanowires with broader light absorption spectrum, up to λ = 1 μm. Both the absorption and photo-luminescence (PL) of the SiNWs are observed from visible to IR wavelengths. It is found that the SiNWs have PL at visible and near Infrared wavelengths, which may infer presence of mechanisms such as forbidden gap transitions other can involvement of plasmonic resonances. Non-radiative recombination of excitons is one of the reasons behind absorption of SiNWs. Also, on the dielectric metal interface, the absorption mechanism can be due to plasmonic dissipation or plasmon-assisted generation of excitons in the indirect band-gap material. Comparison between nanowires with and without metallic nanoparticles has revealed the effect of nanoparticles on absorption enhancement. The broader near IR absorption, paves the way for applications like hyperthermia of cancer while the optical transition in near IR also facilitates harvesting electromagnetic energy at a broad spectrum from visible to IR.

Absorption-line series in Lu I

1972 ◽  
Vol 33 (2-3) ◽  
pp. 197-201 ◽  
Author(s):  
P. Camus ◽  
F.S. Tomkins
Keyword(s):  
Absorption Line

Hydrogen in amorphous Ni–Zr: Pressure concentration isotherms, site occupation, and binding energies

1986 ◽  
Vol 1 (6) ◽  
pp. 765-773 ◽  
Author(s):  
E. Batalla ◽  
J.O. Strom-Olsen ◽  
Z. Altounian ◽  
D. Boothroyd ◽  
R. Harris
Keyword(s):  
Binding Energies ◽  
Site Occupation ◽  
Pressure Concentration

Characterization of Microcrystalline Transition from Amorphous Silicon as a Function of Hydrogen Dilution and Substrate Temperature of Hot-wire CVD

2002 ◽  
Vol 715 ◽  
Author(s):  
Keda Wang ◽  
Haoyue Zhang ◽  
Jian Zhang ◽  
Jessica M. Owens ◽  
Jennifer Weinberg-Wolf ◽  
...  
Keyword(s):  
Substrate Temperature ◽  
Sudden Change ◽  
Chemical Vapor ◽  
Threshold Value ◽  
Ir Absorption ◽  
Sudden Increase ◽  
Hot Wire ◽  
Hydrogen Dilution ◽  
Integral Absorption ◽  
Two Peaks

Abstracta-Si:H films were prepared by hot wire chemical vapor deposition. One group was deposited at a substrate temperature of Ts=250°C with varied hydrogen-dilution ratio, 0<R<10; the other group was deposited with fixed R=3 but a varied Ts from 150 to 550°C. IR, Raman and PL spectra were studied. The Raman results indicate that there is a threshold value for the microstructure transition from a- to μc-Si. The threshold is found to be R ≈ 2 at Ts = 250°C and Ts ≈ 200°C at R=3. The IR absorption of Si-H at 640 cm-1 was used to calculate the hydrogen content, CH. CH decreased monotonically when either R or Ts increased. The Si-H stretching mode contains two peaks at 2000 and 2090 cm-1. The ratio of the integral absorption peaks I2090/(I2090+I2090) showed a sudden increase at the threshold of microcrystallinity. At the same threshold, the PL features also indicate a sudden change from a- to μc-Si., i.e. the low energy PL band becomes dominant and the PL total intensity decreases. We attribute the above IR and PL changes to the contribution of microcrystallinity, especially the c-Si gain-boundaries.

Multiple Donors in Zinc Oxide Substrates

2002 ◽  
Vol 719 ◽  
Author(s):  
K. Thonke ◽  
N. Kerwien ◽  
A. Wysmolek ◽  
M. Potemski ◽  
A. Waag ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Chemical Vapor ◽  
Binding Energies ◽  
Vapor Transport ◽  
Chemical Vapor Transport ◽  
Oxide Substrates ◽  
Multiple Donors ◽  
Major Donors ◽  
Available Zinc ◽  
Transport Technique

AbstractWe investigate by photoluminescence (PL) nominally undoped, commercially available Zinc Oxide substrates (from Eagle Picher) grown by seeded chemical vapor transport technique in order to identify residual donors and acceptors. In low temperature PL spectra the dominant emission comes from the decay of bound exciton lines at around 3.36 eV. Zeeman measurements allow the identification of the two strongest lines and some weaker lines in-between as donorrelated. From the associated two-electron satellite lines binding energies of the major donors of 48 meV and 55 meV, respectively, can be deduced.

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