ESCA Spectra Research Articles

電析法によるＰｔ‐Ｍｏ合金

Pt-Mo alloy films were obtained by electrodeposition from a plating bath containing H2PtCl6 and Na2MoO4, using ammonia alkaline baths, and the effects of electrolysis parameters on Pt and Mo content, the total current efficiency and the structure and thermal stability of Pt-Mo alloy films were investigated under varying conditions of electrolysis.Electrodeposited Pt-Mo alloy films were then studied by X-ray diffraction, DSC analysis and ESCA, and information on the structure of the alloy films was obtained. X-ray diffraction patterns showed that films containing about 10∼15 wt% Mo consisted of a mixture of amorphous and crystalline alloys. ESCA spectra of Mo 3d levels for the alloy films showed that these elements existed in a metallic state.

Über die Konformation eines trinuclearen [1.1.1]Tetramethinium‐Cyaninfarbstoffs mit Indolin‐Endgruppen

Conformation of a Trinuclear [1.1.1]Tetramethinium Cyanine Dye with Indoline End GroupsAccording to its ESCA spectrum (Figure 1) and an X‐ray structural analysis (Figure 2), the [1.1.1]tetramethinium cyanine dye 2 exists in the crystalline state and probably also in solution as methinylogous propeller‐like guanidinium ion 2a with approximate C3 symmetry, and not as vinylogous amidinium ion 2b corresponding to a linear β‐substituted trimethine cyanine dye.

ESCA spectroscopy of poly(methyl methacrylate) grafted onto wood fibers

AbstractThe incompatibility of hydrophilic wood fiber and hydrophobic polymers is the main difficulty with wood thermoplastic polymer composites. To overcome this issue, many researchers suggest grafting polymer onto wood fiber for improving the interfacial adhesion during mixing. A systematic ESCA study of chemi‐thermo‐mechanical pulp (CTMP) grafted fiber has been performed to provide chemical information about surface composition modification. The material analyzed included initial CTMP fiber, the pure polymer i.e., poly(methyl methacrylate) (PMMA) as reference material, and grafted fiber at different polymer loadings. Interest is focused on the carbon and oxygen spectra. Samples at high polymer loading or high grafting level have an O/C, C1, C2, C4, O1, and O2 intensities much similar to those of the PMMA but a little different since some wood fiber sites have still not fixed the polymer. ESCA spectra provide information on about 1–5 nm depth. The ESCA technique allows the monitoring of grafting polymer onto wood fiber as a surface phenomenon.

Glow‐discharge‐induced graft polymerization of acrylic acid onto poly[1‐(trimethylsilyl)‐1‐propyne] film

AbstractGraft polymerization of acrylic acid onto poly[1‐(trimethylsilyl)‐1‐propyne] [poly(TMSP)] film was examined. The water contact angle of poly(TMSP) film decreased remarkably from 90 to 15° by plasma treatment, which gradually increased up to 40° after several days. When the film exposed to a glow discharge was heated in an aqueous solution of acrylic acid at 80°C for 24 h, graft polymerization proceeded on the film surface, which was confirmed by ATR‐IR and ESCA spectra. Graft polymerization effectively occurred above a threshold temperature (80°C). The water contact angle of the grafted film was about 30°, and did not change with time. In contrast, when a poly(TMSP) film exposed to UV irradiation was heated in an aqueous solution of acrylic acid, graft polymerization took place not only on the film surface but also inside the film.

Ion implantation induced change in fibrillar morphology of polyacetylene films

The effects of low-energy ion implantation into a semiconducting polymer on its surface morphology have been studied for films of polyacetylene (CH) x . The samples used in this experiment are normal density (CH) x films, thermally transisomerized in vacuum. Thermionic Na + ions are implanted into these films at energies of about 10 keV. Characterization of the implanted films is carried out by a SEM observation, sheet resistance measurements and ESCA analyses. It is shown that as the ion fluence increases, the fibrils of (CH) x become thick, and at an ion fluence of 7 × 10 16 cm −2 the mean diameter of the fibrils becomes about three times larger than the original value. Such a definite change in morphology is presumably related to stable n-type doping effects reported previously. The ESCA spectra of C 1s and Na 1s for implanted films are consistent with this explanation.

Plasma surface treatments on carbon fibers. II. Mechanical property and interfacial shear strength

AbstractCarbon fiber are surface treated by oxygen, argon, and styrene plasma to study the effects on fiber strength and interfacial shear strength with PPS resin. Interfacial shear strength between carbon fiber and high melting temperature thermoplastic resins is successfully measured with the microbond pull‐out test with the help of scanning CO2 laser beam which solved the difficulties in preparing PPS microspheres. Tensile tests show that etching by oxygen plasma and deposition with plasma–PS increase strength of the fibers in some cases. ESCA spectra deconvolutions demonstrate that the improved interfacial strength is strongly related to the hydroxyl, ether, or aromatic groups on the surface. On the other hand, hydrocarbon segments are detrimental to the interface. Surface area and roughness have little influences on the interfacial strength of carbon fiber/PPS composites.

Quantitative resolution of X‐ray photoelectron spectra of mixtures of chromium compounds by the Kalman filter after cubic spline background removal

AbstractThe potential of a new procedure for the quantitative analysis of ESCA spectra was exploited by determining the composition of powder mixtures of some chromium compounds. The quantitative separation of the overlapped Cr 2p peak doublets was accomplished by the Kalman filter algorithm. Background removal from the spectra was carried out by a new approach employing the cubic splines as smooth interpolators between the peak valleys. The results of the analyses compared well with those obtained by factor analysis (typical errors were ±4%). However, the Kalman filter operating recursively on the data points of the spectrum is preferable when the analysis is limited to only one mixture plus standards. Cubic spline interpolation was as effective as the Shirley method in yielding quantitative background subtraction.

Structure and ESR investigation of plasma‐polymerized film of hexafluoropropene

AbstractThe structure and constitution of plasma‐polymerized film of C3F6 (PPHFP) have been investigated by measuring its ESCA, 19F‐NMR, and IR spectra. It is found that the PPHFP film was a high degree of branching and 57% of quaternary carbons are linked to CF3 groups. It is also found that the constitution of PPHFP film is changed greatly at high power and a large amount of Si and O atoms are linked to the PPHFP chains. Furthermore, using element analysis, ESCA, and theoretical calculation by electronegative model, we found that the nitrogen atoms get into the PPHFP chains when using N2 as plasma gas. Besides, the radical concentration in the film is obtained to be 9.97 × 1019 spins/g and its half‐life is about half a year at room temperature in Ar gas. Having investigated decay process of the radicals in two gases of air and Ar, we calculated the activation energies and rate constants of radical recombination and oxidation reactions at different temperatures.

硫酸クロム（ＩＩＩ）‐カルボン酸塩浴からのＣｒ‐Ｃ合金めっき皮膜の作製

Cr-C alloy plating from Cr (III) sulfate-carboxylate baths has been studied by Hull cell tests and ESCA analysis. Bright deposits were obtained from Cr (III) sulfate baths containing carboxylates such as oxalate, malonate, glycine and some oxycarboxylates. ESCA spectra of C 1s levels for the bright deposits revealed that some of the carbon exists as chromium carbide in the deposits and the rest as adsorbed to be the most feasible complexing agent for Cr (III) resulting in deposits in containing more chromium carbide.

Effect of molecular weight on the ion selective electrochemical polymerization of aniline

The effect of molecular weight on ion selective electrochemical polymerization was investigated. The very small amount of polymer electrolyte added to the electrolyte affects the polymerization rate of aniline. The polyaniline film grows faster and the selectivity is increased when the higher molecular weight of polystyrenesulfonate is used. ESCA spectra revealed the strong interaction of the polystyrenesulfonate with the polyaniline nitrogen atom, which depends on the molecular weight.

Preparation and Spectroscopic Properties of Manganese(II), Chloroiron(III), Cobalt(II), Nickel(II), Copper(II), Zinc(II), and Cadmium(II) Complexes with Hemiporphyrazine

Abstract The manganese(II), chloroiron(III), cobalt(II), nickel(II), copper(II), zinc(II), and cadmium(II) complexes of 5,26:13,18-diimino-7,11:20,24-dinitrilodibenzo[c, n]-l,6,12,17-tetraazacyclo-docosine were prepared and studied by electronic, vibrational, ESR, and ESCA spectroscopy. The metal complexes assume the square-planar configuration types since the ligand field bands were not detected in the region of the 11600-18000 cm−1. A strong band due to the stretching mode of the C=N bond at 1665 cm−1 was shifted to lower frequency upon metal-coordination. ESCA spectra show that there are two kinds of nitrogen atoms in the present metal-free macrocycle and that upon complex formation the eight nitrogens are chemically equivalet in these complexes. Judging from the small Att vaule, the copper(II) complex presumes an essentially planar coordination with distortion toward tetrahedron.

Surface modification by continuous graft copolymerization. I. Photoinitiated graft copolymerization onto polyethylene tape film surface

AbstractA process has been developed for continuous photoinitiated graft copolymerization of acrylamide (AM) and acrylic acid (AA) onto the surface of high‐density polyethylene (HDPE) tape film, presoaked in a solution containing monomer and initiator under nitrogen atmosphere. As photoinitiator we have used benzophenone, which is efficient for photografting of polyolefins with acrylic monomers. The presoaking procedure of the tape film is very important for efficient photografting within short irradiation times. In ESCA spectra of the grafted tape film the relative intensity of the nitrogen over carbon peaks of film grafted with acrylamide is about 5–10% after 6 s irradiation time. The relative intensity of oxygen over carbon peaks in ESCA spectra of film grafted with acrylic acid is about 10–20% after 8 s irradiation time. The effects of varying the monomer concentration in presoaking solution and the different irradiation conditions on the grafting yield have been investigated. This technique has the advantages of being a continuous process with short irradiation times without requirements of vacuum conditions and appears to be promising for practical applications.

The Electrochromic Process at Nb2 O 5 Electrodes Prepared by Thermal Oxidation of Niobium

Electrochromism was studied with layers prepared by thermal oxidation of niobium. The layers are crystalline and the morphology and thickness of these films play an important role in the response of electrochromic process. Cyclic voltammetry and chronopotentiometry were carried out together with ellipsometric measurements in electrochromic region. ESCA spectra of the electroreduced oxide suggest that Nb(V) is reduced to a lower valence state such as Nb(IV), and a chemical bond is formed between H+ inserted into the oxide and O−2 of the oxide. For films the coloration is due to a simultaneous injection of electrons and H+ ions.

Electronic structure calculations Bi 4Ge 3O 12 with the MSXα method. Comparison with experimental data

MSXα calculations are performed on BiO 6 9−, GeO 4 4− and GeO 6 8− clusters in order to describe the electronic structure of the valence band of the scintillator Bi 4Ge 3O 12. From the energetic diagrams, we obtain theoretical photoionization spectra of Bi 2O 3,GeO 2 and Bi 4Ge 3O 12 which are compared to the experimental ESCA spectra. The wavefunctions of particular orbitals relative to the BiO 6 9− cluster, which contains the luminescent centers of Bi 4Ge 3O 12, are plotted in several planes, allowing us to describe the BiBi and BiO bonds in the compound. The assignment of the near UV excitation transitions is performed and found consistent with the experimental data from optical spectroscopy.

Studies on Oxovanadium(IV), Nickel(II), Copper(II), and Palladium(II) Complexes with 5,14-Dihydro-6,8,15,17-Tetramethyldibenzo[b,i][1,4,8,11]Tetraazacyclotetradecine

Abstract The oxovanadium(IV), nickel(II), copper(II), and palladium(II) complexes of 5,14-dihydro-6,8,15,17-tetramethyldibenzo-[b,i][1,4,8,11]tetraazacyclotetradecine have been prepared and investigated by the use of mass, electronic, vibrational, NMR, ESR, and ESCA spectroscopy. In view of the ligand field spectra, the oxovanadium(IV) complex presumes the square-pyramidal configuration and the other complexes assume the square-planar configurations. A strong IR band due to the V=O stretching mode was observed at 970 cm−1 for the oxovanadium(IV) complex. As judged by the spin Hamiltonian parameters, the oxovanadium(IV) complex is in C4v coordination symmetry with an unpaired electron in the dxy orbital and the copper(II) complex is confirmed to have D2h coordination symmetry with an unpaired electron in the dx2−y2 orbital. The result of ESCA spectra is comparable to those obtained for porphyrins.

Studies on Tetraaza[14]tetraene Complexes of Nickel(II) and Copper(II)

Abstract The nickel(II) and copper(II) complexes of tetraaza[14]tetraene were prepared and investigated by means of electronic, vibrational, ESCA and ESR spectroscopy. Judging from the ligand-field spectra, these complexes assume the square-planar configurations. The spin Hamiltonian parameters of the copper(II) complex are also consistent with those for the square-planar coordination. The ESCA spectrum of the metal-free tetraaza[14]tetraene showed double nitrogen ls peaks, whereas that of the complexes exhibited a single nitrogen ls peak.

Reactive ion etching of plasma enhanced chemical vapor deposition amorphous silicon and silicon nitride: Feeding gas effects

Reactive ion etching of PECVD a-Si:H and silicon nitride films was investigated using CF4, C2F6, CHF3, CF3Cl, and CF2Cl2 gases. Under the same power the a-Si:H etch rate decreases in the order of: CF4∼CF3Cl>CF2Cl2>C2F6>CHF3; and the nitride etch rate decreases in the order of: CF4>CF3Cl∼C2F6>CF2Cl2>CHF3. The etch selectivity is controlled by two competitive mechanisms: plasma chemistry and surface reactions. When no surface mass-transfer-limit layer is formed, the plasma phase chemistry dominates the etch rate of the film. For example, the silicon etch rate increases with the chlorine concentration in the plasma phase. When the surface is covered with a thin film, the etch rate is controlled by the ion bombardment energy. For example, the film etch rate in the C2F6 plasma depends on the self-bias voltage only. ESCA and emission spectra results support the above theory.

Reactive Ion Etching of PECVD Amorphous Silicon and Silicon Nitride Thin Films with Fluorocarbon Gases

Plasma‐enhanced chemical vapor deposited (PECVD) amorphous silicon (α‐Si:H) and silicon nitride films have been reactive ion etched with fluorocarbon gases. Process parameters such as power, pressure, and gas flow rate have tremendous effects on etch rates and the etch selectivity. The film etch rate increases with the increase of the power under various pressure and flow rate conditions. Etching mechanisms of three gases (, , and ) are different. With the same gas and etching condition, etching mechanisms of α‐Si:H and nitride are also different. For the plasma, both the plasma‐phase chemistry and the self‐bias voltage control the etch rate and the etch selectivity of nitride to α‐Si:H. For the plasma, the self‐bias voltage dominates the etch rate and the etch selectivity. For the plasma, a self‐bias voltage higher than a threshold voltage is required before the film can be etched. The etch selectivity of nitride to α‐Si:H is greater than one with all etching conditions. An etch selectivity as high as 25 has been obtained with or . ESCA spectra show that the etched surface is clean, the etched surface is probably covered with a carbonaceous layer, and the etched surface is coated with the fluorocarbon polymer.

Processing of conductive polyimide using radiations

PMDA-ODA polyimide is shown to become electrically conducting and optically absorbant on exposure to the 488 nm radiation of an argon ion laser or irradiation with 100 keV Ne + ions. Electron photoelectron spectroscopy has been used to study the chemical modification and structure of the conducting phase induced by irradiation. The ESCA spectrum of the Ne +-irradiated film indicates drastic loss of oxygen and nitrogen resulting in a modified structure. The C 1s spectrum shows these modifications with decarbonylation of the imide group (peak at 288.4 eV) and decrease of the component assigned to carbon in the PMDA ring or carbons bonded to nitrogen or oxygen (285.6 eV), whereas the main C 1s component (284.6 eV) is attributed to graphitic carbon. The plasmon observed at 7.8 eV in the UPS spectrum confirms the graphite-like electronic structure of the treated polyimide. Optical and electrical properties are interpreted by the formation of graphite-like inclusions dispersed in a dielectric matrix. Potential applications in the field of interconnection are discussed.

Surface characteristics of polydimethylsiloxane—poly(methyl methacrylate) block copolymers and their PMMA blends

AbstractTo draw a relationship between surface concentration of the siloxane segment and adhesion performance, surface properties of the polydimethylsiloxane—poly(methyl methacrylate) block copolymers(PDMS‐b‐PMMA) prepared via poly(azo‐containing siloxaneamide)s and their PMMA blends have been studied by measurements of FT‐IR spectra, water contact angle, ESCA spectra and 180° peel strength toward pressure‐sensitive adhesive tape. The water contact angles of the chloroform‐cast blend films increased abruptly with siloxane bulk concentrations, or siloxane contents, particularly, on the air‐side surfaces to reach almost 100° in low siloxane content. A marked increase of the contact angle was observed in the blends containing siloxane chain length (SCL) of longer than 2000. ESCA data evidently confirmed for these blend systems that the siloxane segments with low surface energy were accumulated or enriched mainly on the air‐side surface, and that, on the other hand, polar PMMA segments with high surface energy were oriented to the glass‐side surface and the inside of the films. This surface accumulation behavior of the siloxane segments reflected the 180° peel strength, as a measure of adhesion performance. The water contact angle and 180° peel strength were unequivocally correlated to the siloxane surface concentration estimated from ESCA data. Conversely, in the compression‐molded blend films made by a hydraulic press between a Teflon and a stainless steel plate, the extent of surface accumulation of the PDMS segment was lower than that of the chloroform‐cast films, suggesting lower degree of segment migration in hot‐press films, probably due to substrate surface energy and lower relaxation in the blend melts.