Emissivtty Studies on Polycrystalline Silicon and a-Si / SiO2 / Si

1997 ◽  
Vol 470 ◽  
Author(s):  
W. Chen ◽  
M. Oh ◽  
S. Abedrabbo ◽  
F. M. Tong ◽  
W. Schmidt ◽  
...  
Keyword(s):  
Experimental Data ◽  
Polycrystalline Silicon ◽  
Room Temperature ◽  
Experimental Studies ◽  
Radiative Properties ◽  
Refractive Indices ◽  
Silicon Substrates ◽  
Temperature Dependent ◽  
Open Environment ◽  
Single Side

ABSTRACTExperimental studies of the room temperature emissivity of polysilicon are reported here. These measurements have been performed using a spectral emissometer operating in the wavelength range of 0.8 – 20 μm. The measured optical properties are deconvolved to yield the wavelength dependent refractive indices and extinction coefficient of polysilicon. An in house developed computer program, OPCalc, is deployed to perform these calculations. Experimental results of the temperature dependent emissivity of a-Si / SiO2 / Si / SiO2 / a-Si, fabricated on single side polished silicon substrates, in the temperature range of 300 to 1100 K have been reported here. These measurements are performed for a-Si thickness of 2100A. Comparisons of the temperature dependent radiative properties of these structures between the front and the back show that the contribution of surface roughness to emissivity is negligible- The exposure of these a-Si coated structures to high temperatures in open environment has caused these surfaces to oxidize. Interpretations, have been sought by comparisons of the experimental data with those on SiO2 / Si structures.

Temperature Dependent Line-Shape of the Silicon Dangling Bond EPR-Resonance in Polycrystalline Silicon

1996 ◽  
Vol 452 ◽  
Author(s):  
N. H. Nickel ◽  
E. A. Schiff
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Polycrystalline Silicon ◽  
Room Temperature ◽  
Dangling Bond ◽  
Temperature Dependent ◽  
Paramagnetic Resonance ◽  
Temperature Electron ◽  
Motional Narrowing ◽  
G Value ◽  
Electron Paramagnetic

AbstractThe temperature dependence of the silicon dangling-bond resonance in polycrystalline (poly-Si) and amorphous silicon (a-Si:H) was measured. At room temperature, electron paramagnetic resonance (EPR) measurements reveal an isotropie g-value of 2.0055 and a line width of 6.5 and 6.1 G for Si dangling-bonds in a-Si:H and poly-Si, respectively. In both materials spin density and g-value are independent of temperature. While in a-Si:H the width of the resonance did not change with temperature, poly-Si exhibits a remarkable T dependence of ΔHpp. In unpassivated poly-Si a pronounced decrease of ΔHpp is observed for temperatures above 300 K. At 384 K ΔHpp reaches a minimum of 5.1 G, then increases to 6.1 G at 460 K, and eventually decreases to 4.6 G at 530 K. In hydrogenated poly-Si ΔHpp decreases monotonically above 425 K. The decrease of ΔHpp is attributed to electron hopping causing motional narrowing. An average hopping distance of 15 and 17.5 Å was estimated for unhydrogenated and H passivated poly-Si, respectively.

scholarly journals Theoretical and experimental studies of material radiative properties and their applications to laser and heavy ion inertial fusion

2011 ◽  
Vol 29 (1) ◽  
pp. 69-80 ◽  
Author(s):  
N. Yu. Orlov ◽  
O.B. Denisov ◽  
O.N. Rosmej ◽  
D. Schäfer ◽  
Th. Nisius ◽  
...  
Keyword(s):  
Experimental Data ◽  
Experimental Studies ◽  
Radiation Efficiency ◽  
Radiative Properties ◽  
Wall Material ◽  
Inertial Fusion ◽  
X Rays ◽  
X Ray ◽  
Wide Range ◽  
X Ray Absorption

AbstractTheoretical and experimental studies of radiative properties of substances heated by pulsed current devises or lasers and used as X-ray sources have been carried out depending on plasma conditions, and specific spectra of X-ray absorption and radiation for different materials have been calculated. Important features of the theoretical model, known as the ion model of plasma, are discussed. This model can be applied for calculations of the radiative properties of complex materials over a wide range of plasma parameters. For purposes of indirect-driven inertial fusion based on the hohlraum concept, an optimization method is used for the selection of an effective complex hohlraum wall material, which provides high radiation efficiency at laser interaction with the wall. The radiation efficiency of the resulting material is compared with the efficiency of other composite materials that have previously been evaluated theoretically. A similar theoretical study is performed for the optically thin X-pinch plasma produced by exploding wires. Theoretical estimations of radiative efficiency are compared with experimental data that have been obtained from measurements of X-pinch radiation energy yield using two exploding wire materials, NiCr and Alloy 188. It is shown that the theoretical results agree well with the experimental data. A symmetric multilayer X-pinch, where W and Mo wires are used, is as well considered. The theoretical explanation of experimental phenomena is discussed based on the W and Mo radiative spectra. The ion model was as well applied for interpretation of experimental results on opacities of CHO-plasma obtained via indirect heating of low density polymer layers by means of soft X-rays. The new diagnostics method based on the deformation of the of the Carbon absorption K-edge when foam layer is heated to plasma is discussed. The spectral coefficients for X-ray absorption in CHO-plasma are calculated in the photon energy region around the Carbon K-edge for different plasma temperatures and mean foam density. In this case, the Carbon K-edge position on the energy scale can be used for plasma temperature diagnostic.

scholarly journals Theoretical and experimental studies of the radiative properties of hot dense matter for optimizing soft X-ray sources

2007 ◽  
Vol 25 (3) ◽  
pp. 415-423 ◽  
Author(s):  
N.Yu. Orlov ◽  
S.Yu. Gus'kov ◽  
S.A. Pikuz ◽  
V.B. Rozanov ◽  
T.A. Shelkovenko ◽  
...  
Keyword(s):  
Experimental Data ◽  
Theoretical Calculations ◽  
Experimental Studies ◽  
Dense Matter ◽  
Radiation Energy ◽  
Radiative Properties ◽  
Theoretical Research ◽  
Energy Yield ◽  
X Ray ◽  
Dense Plasmas

Theoretical and experimental studies of radiative properties of hot dense plasmas that are used as soft X-ray sources have been carried out depending on the plasma composition. Important features of the theoretical model, which can be used for complex materials, are discussed. An optimizing procedure that can determine an effective complex material to produce optically thick plasma by laser interaction with a thick solid target is applied. The efficiency of the resulting material is compared with the efficiency of other composite materials that have previously been evaluated theoretically. It is shown that the optimizing procedure does, in practice, find higher radiation efficiency materials than have been found by previous authors. Similar theoretical research is performed for the optically thin plasma produced from exploding wires. Theoretical estimations of radiative efficiency are compared with experimental data that are obtained from measurements of X-pinch radiation energy yield using two exploding wire materials, NiCr and Alloy 188. It is shown that theoretical calculations agree well with the experimental data.

scholarly journals Synthesis and Thermochromic Luminescence of Ag(I) Complexes Based on 4,6-Bis(diphenylphosphino)-Pyrimidine

Inorganics ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 46
Author(s):  
Alexander V. Artem’ev ◽  
Maria P. Davydova ◽  
Alexey S. Berezin ◽  
Denis G. Samsonenko
Keyword(s):  
Experimental Data ◽  
Coordination Mode ◽  
Room Temperature ◽  
Delayed Fluorescence ◽  
Coordination Pattern ◽  
Temperature Dependent ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated ◽  
1D Coordination Polymer ◽  
Metal Organic

Two Ag(I)-based metal-organic compounds have been synthesized exploiting 4,6-bis(diphenylphosphino)pyrimidine (L). The reaction of this ligand with AgNO3 and AgBF4 in acetonitrile produces dinuclear complex, [Ag2L2(MeCN)2(NO3)2] (1) and 1D coordination polymer, [Ag2L(MeCN)3]n(BF4)2n (2), respectively. In complex 1, µ2-P,P′-bridging coordination pattern of the ligand L is observed, whereas its µ4-P,N,N′,P′-coordination mode appears in 2. Both compounds exhibit pronounced thermochromic luminescence expressed by reversible changing of the emission chromaticity from a yellow at 300 K to an orange at 77 K. At room temperature, the emission lifetimes of 1 and 2 are 15.5 and 9.4 µs, the quantum efficiency being 18 and 56%, respectively. On account of temperature-dependent experimental data, the phenomenon was tentatively ascribed to alteration of the emission nature from thermally activated delayed fluorescence at 300 K to phosphoresce at 77 K.

(111) Monocrystalline Nickel Films

1972 ◽  
Vol 30 ◽  
pp. 512-513
Author(s):  
T.E. Pratt ◽  
R.W. Vook
Keyword(s):  
Film Thickness ◽  
Deposition Rate ◽  
Room Temperature ◽  
Narrow Range ◽  
High Vacuum ◽  
Residual Pressure ◽  
Temperature Dependent ◽  
Deposition Parameters ◽  
Transmission Electron ◽  
Substrate Temperatures

(111) oriented thin monocrystalline Ni films have been prepared by vacuum evaporation and examined by transmission electron microscopy and electron diffraction. In high vacuum, at room temperature, a layer of NaCl was first evaporated onto a freshly air-cleaved muscovite substrate clamped to a copper block with attached heater and thermocouple. Then, at various substrate temperatures, with other parameters held within a narrow range, Ni was evaporated from a tungsten filament. It had been shown previously that similar procedures would yield monocrystalline films of CU, Ag, and Au.For the films examined with respect to temperature dependent effects, typical deposition parameters were: Ni film thickness, 500-800 A; Ni deposition rate, 10 A/sec.; residual pressure, 10-6 torr; NaCl film thickness, 250 A; and NaCl deposition rate, 10 A/sec. Some additional evaporations involved higher deposition rates and lower film thicknesses.Monocrystalline films were obtained with substrate temperatures above 500° C. Below 450° C, the films were polycrystalline with a strong (111) preferred orientation.

Evidence for ordered Fe3Ni

1987 ◽  
Vol 45 ◽  
pp. 216-217
Author(s):  
K.B. Reuter ◽  
D.B. Williams ◽  
J.I. Goldstein
Keyword(s):  
Experimental Data ◽  
Martensitic Transformation ◽  
Electron Diffraction ◽  
Room Temperature ◽  
Direct Evidence ◽  
Transformation Product ◽  
Iron Meteorites ◽  
X Ray ◽  
Ni Content ◽  
Temperature Transformation

In the Fe-Ni system, although ordered FeNi and ordered Ni3Fe are experimentally well established, direct evidence for ordered Fe3Ni is unconvincing. Little experimental data for Fe3Ni exists because diffusion is sluggish at temperatures below 400°C and because alloys containing less than 29 wt% Ni undergo a martensitic transformation at room temperature. Fe-Ni phases in iron meteorites were examined in this study because iron meteorites have cooled at slow rates of about 10°C/106 years, allowing phase transformations below 400°C to occur. One low temperature transformation product, called clear taenite 2 (CT2), was of particular interest because it contains less than 30 wtZ Ni and is not martensitic. Because CT2 is only a few microns in size, the structure and Ni content were determined through electron diffraction and x-ray microanalysis. A Philips EM400T operated at 120 kV, equipped with a Tracor Northern 2000 multichannel analyzer, was used.

Spectrum of Defect States in Porous Organic Low-k Dielectric Films, Annealed in Argon and Nitrogen

2003 ◽  
Vol 766 ◽  
Author(s):  
V. Ligatchev ◽  
T.K.S. Wong ◽  
T.K. Goh ◽  
Rusli Suzhu Yu
Keyword(s):  
Deep Level ◽  
Dielectric Films ◽  
Silicon Substrates ◽  
Reverse Bias Voltage ◽  
Defect States ◽  
Single Side ◽  
Sandwich Type ◽  
Transient Spectroscopy ◽  
P Type ◽  
Spectrum Deconvolution

AbstractDefect spectrum N(E) of porous organic dielectric (POD) films is studied with capacitance deep-level-transient-spectroscopy (C-DLTS) in the energy range up to 0.7 eV below conduction band bottom Ec. The POD films were prepared by spin coating onto 200mm p-type (1 – 10 Δcm) single-side polished silicon substrates followed by baking at 325°C on a hot plate and curing at 425°C in furnace. The film thickness is in the 5000 – 6000 Å range. The ‘sandwich’ -type NiCr/POD/p-Si/NiCr test structures showed both rectifying DC current-voltage characteristics and linear 1/C2 vs. DC reverse bias voltage. These confirm the applicability of the C-DLTS technique for defect spectrum deconvolution and the n-type conductivity of the studied films. Isochronal annealing (30 min in argon or 60 min in nitrogen) has been performed over the temperature range 300°C - 650°C. The N(E) distribution is only slightly affected by annealing in argon. However, the distribution depends strongly on the annealing temperature in nitrogen ambient. A strong N(E) peak at Ec – E = 0.55 – 0.60 eV is detected in all samples annealed in argon but this peak is practically absent in samples annealed in nitrogen at Ta < 480°C. On the other hand, two new peaks at Ec – E = 0.12 and 0.20 eV appear in the N(E) spectrum of the samples annealed in nitrogen at Ta = 650°C. The different features of the defect spectrum are attributed to different interactions of argon and nitrogen with dangling carbon bonds on the intra-pore surfaces.

Diagnostics of metal samples using the results of experimental and theoretical study of positively charged microparticles formed upon sample destruction

2018 ◽  
Vol 84 (10) ◽  
pp. 23-28
Author(s):  
D. A. Golentsov ◽  
A. G. Gulin ◽  
Vladimir A. Likhter ◽  
K. E. Ulybyshev
Keyword(s):  
Experimental Data ◽  
Early Stage ◽  
Experimental Studies ◽  
Material Model ◽  
Total Charge ◽  
Cross Sectional ◽  
Practical Applications ◽  
Mechanical And Electrical Properties ◽  
Order Of Magnitude ◽  
Using Data

Destruction of bodies is accompanied by formation of both large and microscopic fragments. Numerous experiments on the rupture of different samples show that those fragments carry a positive electric charge. his phenomenon is of interest from the viewpoint of its potential application to contactless diagnostics of the early stage of destruction of the elements in various technical devices. However, the lack of understanding the nature of this phenomenon restricts the possibility of its practical applications. Experimental studies were carried out using an apparatus that allowed direct measurements of the total charge of the microparticles formed upon sample rupture and determination of their size and quantity. The results of rupture tests of duralumin and electrical steel showed that the size of microparticles is several tens of microns, the particle charge per particle is on the order of 10–14 C, and their amount can be estimated as the ratio of the cross-sectional area of the sample at the point of discontinuity to the square of the microparticle size. A model of charge formation on the microparticles is developed proceeding from the experimental data and current concept of the electron gas in metals. The model makes it possible to determine the charge of the microparticle using data on the particle size and mechanical and electrical properties of the material. Model estimates of the total charge of particles show order-of-magnitude agreement with the experimental data.

ИССЛЕДОВАНИЕ МАГНИТОРЕЗИСТИВНЫХ НАНОСТРУКТУР С МАГНИТОСТРИКЦИОННЫМ ЭФФЕКТОМ ДЛЯ УСТРОЙСТВ МАГНИТНОЙ СТРЕЙНТРОНИКИ

2020 ◽  
Vol 96 (3s) ◽  
pp. 420-423
Author(s):  
Д.А. Жуков ◽  
В.В. Амеличев ◽  
Д.В. Костюк ◽  
А.И. Крикунов ◽  
Д.В. Васильев ◽  
...  
Keyword(s):  
Thin Film ◽  
Experimental Studies ◽  
Silicon Substrates ◽  
Multilayer Nanostructures ◽  
Magnetoresistive Effect ◽  
Anisotropic Magnetoresistive Effect

Представлены результаты экспериментальных исследований магнитострикционных и магниторезистивных свойств тонкопленочных многослойных наноструктур Ta/FeNiCo/CoFe/Ta и Ta/FeNiCo/CoFeВ/Ta на окисленных кремниевых подложках диаметром 100 мм. Экспериментально установлена зависимость величины анизотропного магниторезистивного эффекта от величины механических деформаций в экспериментальных образцах наноструктур. The paper presents the results of experimental studies of the magnetostriction and magnetoresistive properties of thin-film multilayer nanostructures Ta/FeNiCo/CoFe/Ta and Ta/FeNiCo/CoFeB/Ta on oxidized silicon substrates with a diameter of 100 mm. The dependence of the magnitude of the anisotropic magnetoresistive effect on the magnitude of mechanical strains in experimental samples of nanostructures has been experimentally established.

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