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Rutherford Backscattering Spectrometry (rutherford + backscattering_spectrometry)
Selected AbstractsMagnetic characterization of U/Co multilayersPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 1 2003M. A. Rosa Abstract With the aim of expanding the studies on 2D systems containing uranium, U/Co multilayers with layer thickness ranging from 50 to 200 Å were recently prepared by dc magnetron sputtering onto glass. The multilayers were characterized by Grazing-Incidence X-Ray Diffraction (GIXRD) and Rutherford Backscattering Spectrometry (RBS). Magnetization measurements performed with a squid magnetometer showed that the multilayers have a ferromagnetic behaviour, with the magnetic signal increasing with the thickness of the layers. The analysis of magnetic anisotropy evidenced an easy magnetic direction in the film plane with large anisotropy fields, which increase with the thickness of the layers and suggests a positive contribution of surface anisotropy to the effective anisotropy Keff. [source] Nitrided Amorphous Stainless Steel Coatings Deposited by Reactive Magnetron Sputtering from an Austenitic Stainless Steel TargetADVANCED ENGINEERING MATERIALS, Issue 1-2 2009Salvatore Cusenza Abstract Stainless steel films were reactively magnetron sputtered in argon/nitrogen gas flow onto oxidized silicon wafers using austenitic AISI 316 stainless-steel targets. The deposited films of about 300,nm thickness were characterized by conversion electron Mö-i;ssbauer spectroscopy, magneto-optical Kerr-effect, X-ray diffraction, Rutherford backscattering spectrometry, and resonant nuclear reaction analysis. These complementary methods were used for a detailed examination of the nitriding effects for the sputtered stainless-steel films. The formation of an amorphous and soft ferromagnetic phase in a wide range of the processing parameters was found. Further, the influence of postvacuum-annealing was examined by perturbed angular correlation to achieve a comprehensive understanding of the nitriding process and phase formation. The amorphous phase is not very stable and crystallization can be observed at 973,K. [source] Characterization of parylene-N and parylene-C photooxidationJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 10 2003K. G. Pruden Abstract Parylene-N and parylene-C are polymers of interest for microelectronic and medical coating applications. Modifications for improved surface properties could make them even more useful in such applications. Parylene-N and parylene-C films were exposed to ultraviolet light in the presence of oxygen and analyzed with Rutherford backscattering spectrometry, secondary-ion mass spectroscopy, X-ray photoelectron spectroscopy, and infrared spectroscopy. This study shows that such exposure results in the formation of aldehyde and carboxylic acid groups near the surface of the films. At the maximum exposure dose, the concentration of oxygen in both parylene-N and parylene-C is about 13% at the film surface, and it decreases exponentially with increasing depth. Further modeling and optimization of this process would allow it to be used to tailor the surface concentration of oxygenated species in parylene for the optimization of adhesion and wettability or for the chemical binding of other moieties. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 1486,1496, 2003 [source] Micro-Raman study of iridium silicidesJOURNAL OF RAMAN SPECTROSCOPY, Issue 2 2002A. Almendra The micro-Raman spectra of three iridium silicides, IrSi, IrSi1.75 and IrSi3, were obtained. The silicides were prepared by rapid thermal annealing of iridium films deposited on Si substrates. The three phases were identified by Rutherford backscattering spectrometry. The main bands observed in the micro-Raman spectra are described in order to provide a simple characterization method for these silicides with high spatial resolution. The three silicides present phonon bands around 165 and 200 cm,1. Some additional broad bands between 240 and 500 cm,1 were also observed. Copyright © 2002 John Wiley & Sons, Ltd. [source] Effect of Sr adsorption on stability of and epitaxial SrTiO3 growth on Si(001) surfacePHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 9 2006Y. Liang Abstract The geometric and electronic structures of the Sr adsorbed Si(001) surface were investigated using photoemission spectroscopy, electron diffraction, scanning tunneling microscopy, and Rutherford backscattering spectrometry. Results showed that the Sr adsorbed Si(001) exhibited several reconstructions depending upon the Sr coverage. Photoemission results revealed that at one half mono-layer of Sr coverage the dimer-derived surface states disappeared and the stability of Si increased accordingly against oxidation at elevated temperatures. Using this Sr covered surface as a template, epitaxial SrTiO3 films were grown on the vicinal Si(001) substrates using molecular beam epitaxy. The growth process is explained in terms of kinetically limited reaction facilitated by a local energy minimum induced by the Sr adsorption at Si(001) surface. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Microstructure of diamond-like carbon films prepared using acetylene and toluene by bipolar-type plasma based ion implantationPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 4 2008S. Nakao Abstract Diamond-like carbon (DLC) films are deposited on Si substrates using acetylene (C2H2), toluene (C7H8) and their mixed gas, and the microstructures are examined by micro-Raman spectroscopy, Rutherford backscattering spectrometry (RBS) and elastic recoil detection (ERD) analysis as a function of negatively pulsed voltages (Vn). It is found that the formation of graphite-like structure (aromatic ring clustering) is enhanced with increasing Vn. In addition, the density of the films is increased up to approximately 2.0 g/cm3 and the H concentration is decreased with increasing Vn. The use of C2H2 has much effect on the formation of graphite-like structure and the reduction of H concentration in the films at high Vn as compared with others. The deposition rate of the films is increased with increasing Vn. Relatively high deposition rate is obtained when using C7H8. In the case of the mixed gas, the deposition rate is found to be close to that of C7H8. These results suggest that C7H8 is dominant to the deposition process when using the mixture of C2H2 + C7H8. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Influence of a polymeric solution buffer layer on the chemical bath deposition of polycrystalline PbS filmsPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 10 2005Y. González-Alfaro Abstract Polycrystalline thin films of PbS grown on glass substrates previously coated with PbS colloidal particles in a polyvinyl alcohol solution were obtained by chemical bath deposition (CBD). The X-ray diffraction procedures showed evidence of polycrystalline films of cubic PbS with a preferred normal orientation of the planes [100] with the growth direction. The film texture showed a strong influence of the initial conditions of the surface. Moreover, changes in colour, morphology and grain size of the films were observed by optic and atomic force microscopy (AFM). Rutherford backscattering spectrometry (RBS) showed a dependence of the thickness and roughness of the PbS films with the growth initial conditions. A kinetic growth model is proposed to explain the changes in the structure and morphology of the PbS. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Degradation of Structural and Optical Properties of InGaN/GaN Multiple Quantum Wells with Increasing Number of WellsPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 1 2003S. Pereira Abstract We compare the structural and spectral properties of two multi quantum wells (MQWs), grown by metal organic chemical vapour deposition under the same nominal conditions, with a different number of periods. The MQWs, each with 20% InN and containing 8 and 18 wells, respectively, grew on-axis and coherent to GaN, as revealed by X-ray diffraction reciprocal space mapping (RSM) analysis. Comparison of the asymmetrical (105) RSMs indicates an overall structural deterioration and greater well-barrier intermixing for the MQW with the larger number of wells. Moreover, the composition of the MQWs was depth-profiled by grazing incidence Rutherford backscattering spectrometry (RBS). RBS further evidences strong intermixing in the 18-well heterostructure. The deleterious effects of intermixing on the emission spectrum are revealed by low temperature photoluminescence spectroscopy. Despite similar peak emission energies (,E < 45 meV) the 8-well structure shows a more symmetric and narrow peak (FWHM , 100 meV) in comparison with that of the 18-well sample (FWHM , 170 meV). Surface analyses by atomic force and scanning electron microscopy show an increased density, size and depth of V-pit defects on the 18-well structure. These results suggest that dislocations and pitting result from a larger elastic strain energy accumulated in the thicker MQW stack and are a fundamental intermixing mechanism for InGaN/GaN MQWs. [source] Oscillations of the critical temperature in superconducting Nb/Ni bilayersANNALEN DER PHYSIK, Issue 1-2 2003A.S. Sidorenko Abstract We investigated Nb/Ni bilayers prepared by magnetron sputtering on glass subtrates. The quality of the films was characterized by small-angle X-ray diffraction analysis. The thickness of the layers was determined by the Rutherford backscattering spectrometry (RBS). For specimens with constant Nb layer thickness we observed distinct oscillations of the superconducting critical temperature upon increasing the thickness of the Ni layer. The results are interpreted in terms of Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) like inhomogeneous superconducting pairing in the ferromagnetic Ni Layer. [source] Deposition of Niobium Nitride Thin Films from Tert -Butylamido- Tris -(Diethylamido)-Niobium by a Modified Industrial MOCVD ReactorCHEMICAL VAPOR DEPOSITION, Issue 10-12 2009Tobias B. Thiede Abstract Niobium nitride thin films are deposited on 2, silicon (100) wafers using a modified industrial metal-organic (MO) CVD reactor of the type AIX-200RF, starting from tert -butylamido- tris -(diethylamido)-niobium (TBTDEN) and ammonia. Films of thicknesses 50-200,nm are deposited at temperatures ranging from 400,°C to 800,°C under reactor pressures of 1 and 5 mbar using various ammonia flow rates, and are characterized by the use of complementary techniques, namely X-ray diffraction (XRD), scanning electron microscopy (SEM), secondary neutral mass spectrometry (SNMS), Rutherford backscattering spectrometry (RBS), X-ray photoelectron spectroscopy (XPS), and electrical measurements. Films deposited above 450,°C consist of the cubic , -NbN phase, apart from the presence of Nb-O and Nb-O-N species predominantly in the outermost film regions. The lowest specific resistivities, determined by four point probe measurements, are in the range 500,600,µ, cm. A NbN/SiO2/p-Si gate stack is fabricated using the grown niobium nitride films. From the capacitance-voltage (C - V)-curves, flat-band voltages are extracted which, when plotted against SiO2 -insulator thickness, yield a work function of 4.72,eV for as-deposited films. [source] Dehydrohalogenation in Alpha-Functionalized Poly- p -xylylenes,CHEMICAL VAPOR DEPOSITION, Issue 4 2006P. Carrow Abstract Poly(p -xylylene) or parylene has been around for more than a half a century. It is typically deposited by the Gorham method from [2.2] paracyclophane. However, another method is via alpha-derivatives of p -xylene. Both poly(,-bromo- p -xylylene) and poly(,-chloro- p -xylylene) have been successfully deposited by this route through predominately HBr or HCl dehydrohalogenation gas-phase reactions. In the study reported here we synthesize ,,,,,-tribromo- p -xylene and ,-bromo-,,,,,-dichloro- p -xylene as CVD precursors to yield ,,,- and ,,,,-dihalogenated poly(p -xylylene)s to try to convert them, via post-deposition annealing, to poly(phenylene ethynylene) (PPE). PPE and its intermediate poly(phenylene vinylene) (PPV), have potentially better thermal and oxidative properties, and in addition they are both photoluminescent. The as-deposited and annealed thin films have been characterized by Rutherford backscattering spectrometry (RBS), infrared spectroscopy, and UV-vis spectrophotometry, and electrically tested by dielectric constant, bias-temperature stress (BTS), and leakage current. It is found that the thin films crystallizes concurrent with the formation of PPV and possibly converts to PPE but has much residual chlorine and bromine. However, PPV exhibits excellent stability in contact with copper and is more thermally stable than poly(p -xylylene). [source] | |||||||||||||