scholarly journals Влияние неравновесных условий синтеза на структуру и оптические свойства аморфных углеродных пленок

2019 ◽  
Vol 127 (8) ◽  
pp. 251
Author(s):  
А.П. Рягузов ◽  
Р.Р. Немкаева ◽  
О.И. Юхновец ◽  
Н.Р. Гусейнов ◽  
С.Л. Михайлова ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Local Structure ◽  
Carbon Films ◽  
Phonon Density ◽  
Plasma Current ◽  
Phonon Density Of States ◽  
Graphite Target ◽  
X Ray ◽  
Plasma Sputtering ◽  
Ion Plasma

Amorphous carbon (a-C) thin films were synthesized by non-equilibrium method of ion-plasma sputtering of graphite target in Ar atmosphere at constant value of plasma current. Studies of the local structure of the carbon films were carried out using Raman spectroscopy method. Using normal distribution for Raman spectra decomposition it was revealed that at synthesis temperatures below 150 C a peak at about 1260 cm-1 occurred, which is characteristic for phonon density of states with sp3-hybridized bonds. In addition, it was shown the dependence of the optical bandgap on the sizes of sp2-site nanostructures and correlation of it with the results of X-ray photoelectron spectroscopy (XPS) in the a-C films.

scholarly journals Vibrational anisotropy of <i>δ</i>-(Al,Fe)OOH single crystals as probed by nuclear resonant inelastic X-ray scattering

2021 ◽  
Vol 33 (4) ◽  
pp. 485-502
Author(s):  
Johannes Buchen ◽  
Wolfgang Sturhahn ◽  
Takayuki Ishii ◽  
Jennifer M. Jackson
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Single Crystals ◽  
Vibrational Properties ◽  
Phonon Density ◽  
Phonon Density Of States ◽  
X Ray ◽  
X Ray Scattering ◽  
The Mean ◽  
Vibrational Anisotropy

Abstract. The formation of high-pressure oxyhydroxide phases spanned by the components AlOOH–FeOOH–MgSiO2(OH)2 in experiments suggests their capability to retain hydrogen in Earth's lower mantle. Understanding the vibrational properties of high-pressure phases provides the basis for assessing their thermal properties, which are required to compute phase diagrams and physical properties. Vibrational properties can be highly anisotropic, in particular for materials with crystal structures of low symmetry that contain directed structural groups or components. We used nuclear resonant inelastic X-ray scattering (NRIXS) to probe lattice vibrations that involve motions of 57Fe atoms in δ-(Al0.87Fe0.13)OOH single crystals. From the recorded single-crystal NRIXS spectra, we calculated projections of the partial phonon density of states along different crystallographic directions. To describe the anisotropy of central vibrational properties, we define and derive tensors for the partial phonon density of states, the Lamb–Mössbauer factor, the mean kinetic energy per vibrational mode, and the mean force constant of 57Fe atoms. We further show how the anisotropy of the Lamb–Mössbauer factor can be translated into anisotropic displacement parameters for 57Fe atoms and relate our findings on vibrational anisotropy to the crystal structure of δ-(Al,Fe)OOH. As a potential application of single-crystal NRIXS at high pressures, we discuss the evaluation of anisotropic thermal stresses in the context of elastic geobarometry for mineral inclusions. Our results on single crystals of δ-(Al,Fe)OOH demonstrate the sensitivity of NRIXS to vibrational anisotropy and provide an in-depth description of the vibrational behavior of Fe3+ cations in a crystal structure that may motivate future applications of NRIXS to study anisotropic vibrational properties of minerals.

Surface Analysis of Carbon–Hydrogen Bonds in Diamondlike Carbon Films by X-ray Photoelectron Spectroscopy

2009 ◽  
Vol 48 (9) ◽  
pp. 092304 ◽  
Author(s):  
Susumu Takabayashi ◽  
Keishi Okamoto ◽  
Tatsuyuki Nakatani ◽  
Hiroyuki Sakaue ◽  
Takayuki Takahagi
Keyword(s):  
Hydrogen Bonds ◽  
Surface Analysis ◽  
Photoelectron Spectroscopy ◽  
Carbon Films ◽  
X Ray ◽  
Diamondlike Carbon ◽  
Carbon Hydrogen Bonds

scholarly journals Anisotropic phonon density of states: the application of Rietveld and Mössbauer texture analysis in aligned powders

2009 ◽  
Vol 42 (3) ◽  
pp. 496-501 ◽  
Author(s):  
A. I. Rykov ◽  
M. Seto ◽  
Y. Ueda ◽  
K. Nomura
Keyword(s):  
Single Crystals ◽  
Angular Dependence ◽  
Density Of States ◽  
Rietveld Analysis ◽  
Phonon Density ◽  
X Rays ◽  
Phonon Density Of States ◽  
Thermal Displacement ◽  
X Ray ◽  
Arbitrary Strength

Since it is not always feasible to synthesize single crystals of novel materials, the orientation of layered polycrystals has become an attractive basis for studying the angular dependence of inelastic scattering of X-rays or neutrons. Utilizing Rietveld analysis, the anisotropic properties of layered structures in novel manganites and cuprates have been studied with oriented powders instead of single crystals. The phonon density of states (DOS) and atomic thermal displacement are anisotropic in theA-site-ordered manganites LnBaMn2Oyfor the seriesy= 5 andy= 6 (Ln = Y, La, Sm and Gd). This article establishes the angular dependence of the DOS on texture of arbitrary strength, links the textures observed by X-ray and γ-ray techniques, and solves the problem of disentanglement of the Goldanskii–Karyagin effect and texture in Mössbauer spectra.

Optical Properties of Diamond-Like Carbon Films Modified by Platinum

2013 ◽  
Vol 660 ◽  
pp. 47-50 ◽  
Author(s):  
Oleg Prikhodko ◽  
Nurlan Manabaev ◽  
Nazim Guseynov ◽  
Suyumbika Maksimova ◽  
Svetlana Mikhailova ◽  
...  
Keyword(s):  
Optical Properties ◽  
Plasmon Resonance ◽  
Carbon Films ◽  
Diamond Like Carbon ◽  
Metal Nanoclusters ◽  
Plasma Sputtering ◽  
Ion Plasma

ion plasma sputtering, carbon diamond-like films, modification, metal nanoclusters, optical properties, plasmon resonance.

Influence of in-process copper incorporation on the quality of diamond-like carbon films deposited by pulsed laser deposition technique

1996 ◽  
Vol 11 (9) ◽  
pp. 2236-2241 ◽  
Author(s):  
S. J. Dikshit ◽  
Pramada Lele ◽  
S.B. Ogale ◽  
S. T. Kshirsagar
Keyword(s):  
Photoelectron Spectroscopy ◽  
Copper Concentration ◽  
Laser Energy ◽  
Carbon Films ◽  
Laser Deposition ◽  
Deposition Technique ◽  
X Ray ◽  
Glass Substrates ◽  
Pure Graphite ◽  
Composite Pellets

Copper-incorporated carbon films have been prepared on Si(100) and Corning (7059) glass substrates by the pulsed excimer laser deposition technique using KrF radiation (λ = 248 nm). Cold-pressed composite pellets, having compositions from 2 at. % to 11 at. % copper in carbon, were used as targets for ablation. Good quality, scratch-proof films were obtained at a laser energy density of 2−3 J/cm2 and a substrate temperature of 50 °C. The films were characterized by x-ray diffraction (XRD), Raman spectroscopy, x-ray photoelectron spectroscopy (XPS), UV-visible spectrometry, ellipsometry, and four-point probe resistivity measurements. Under similar deposition conditions, films obtained from composite targets of lower copper concentration are seen to have better diamond-like character as compared to those obtained from a pure graphite target. At such low concentrations, copper is seen to cluster in the form of nanoparticles. As the copper concentration increases in the films, they tend to acquire disordered graphitic network with degraded DLC characteristics, and the size of copper agglomerates increases from about 5 nm (for the 2 at. % case) to 85 nm (for the 11 at. % case). It is seen that an increase in the copper content leads to modifications in the carbon network, additional interband transitions, and reduction of the band gap.

Studies of C60 Films Deposited Using Ionized Cluster Beam Deposition Technique

1994 ◽  
Vol 349 ◽  
Author(s):  
Zhong-Min Ren ◽  
Yuan-Cheng Du ◽  
Zhi-Feng Ying ◽  
Xia-Xing Xiong ◽  
Mao-Qi He ◽  
...  
Keyword(s):  
Raman Spectra ◽  
Photoelectron Spectroscopy ◽  
Carbon Films ◽  
Cluster Beam ◽  
Visible Absorption ◽  
Carbon Allotrope ◽  
X Ray ◽  
Hexagonal Close Packed Structure ◽  
Cluster Beam Deposition ◽  
Beam Deposition

ABSTRACTFilms (with thicknesses about thousands A) of a new form of carbon allotrope, CIO also known as Fullerenes, are deposited on Si(111) substrates using ionized cluster beam deposition (ICBD) technique at low (65V) accelerating voltage V. X-ray &-20 diffraction (XRD) have been used to investigate the structural properties of C6Ofi lms, indicating hexagonal close-packed structure with strong (002) XRD assignment together with weak (100), (112) and(004) assignments. Raman spectra, X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES) are carried out to make detailed studies of the electronic properties of the films and to illustrate differences between CO films and amorphous carbon films which are deposited by ICBD at high accelerating voltage V >400V. Cio soccer-balls are found to be broken into fragments as accelerating field overtakes about 400V, indicated by the results of XPS, Raman spectra, XRD, and UV/visible absorption spectra.

Effect of R.F. Power on Structures and Properties of Amorphous Fluorinated Carbon Films Prepared by PSII

2007 ◽  
Vol 353-358 ◽  
pp. 1829-1832
Author(s):  
Guang Ze Tang ◽  
Xin Xin Ma ◽  
Ming Ren Sun
Keyword(s):  
Photoelectron Spectroscopy ◽  
Cluster Structure ◽  
Indentation Test ◽  
Plasma Source ◽  
Carbon Films ◽  
Power Structures ◽  
X Ray ◽  
Structures And Properties ◽  
Plasma Source Ion Implantation ◽  
Structure Density

Fluorinated amorphous carbon films (a-C:H:F) were deposited by plasma source ion implantation (PSII) with precursor gas of CH2FCF3 + C2H2 + H2 with various radio frequency (r.f.) power. Structures and properties evolution varied with r.f. power was discussed in detail. X-ray photoelectron spectroscopy (XPS), Raman spectrum, X-Ray reflection(XRR), atomic force microscopy (AFM) were used to analyze composition, chemical state, sp2 cluster structure, density and surface morphology of prepared films. Nano-indentation test was used to get hardness and modulus. The results show that with the increase of r.f. power, the size and amount of sp2 cluster increase, so does the surface roughness; however, the density and the hardness of films decrease.

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