苯并三氮唑对铜和铁缓蚀作用的拉曼光谱研究

本文利用现场拉曼光谱研究了中性含氯离子溶液中苯并三氮唑在铜和铁电极表面的吸附以及成膜行为,结果表明苯并三氮唑能强烈地化学吸附于铜电极和铁电极表面,形成类似［Ｍｎ（ＢＴＡ）ｐ］的配合物膜,一定程度上阻止了膜内外物质的交换,对金属起缓蚀作用。另一方面两种金属表面配合物膜均具有电位依赖性：在铜电极表面,当外加电位由－０．５Ｖ负移至－０．９Ｖ时,发生了由［Ｃｕ（Ⅰ）（ＢＴＡ）］ｎ向［Ｃｕ（Ⅰ）Ｃｌ（ＢＴＡＨ）］４的转变;而在铁电极表面当外加电位由－０．６Ｖ负移至－１．２Ｖ时,最初形成的表面配合物［Ｆｅｎ（ＢＴＡ）ｐ］则很可能转变成类似于［Ｆｅｎ（Ｃｌ）ｐ（ＢＴＡＨ）ｍ］的配合物,从而使得ＢＴＡＨ对铜、铁的缓蚀能力均有所下降。     

First principle calculations of benzotriazole adsorption onto clean Cu(1 1 1)

The adsorption of benzotriazole (BTAH or C₆N₃H₅) on a Cu(1 1 1) surface is investigated by using first principle density functional theory calculations (VASP). It is found that BTAH can be physisorbed (<0.1 eV) or weakly chemisorbed (∼0.43 eV) onto Cu(1 1 1), and the chemical bond is formed through nitrogen sp² lone pairs. The weak chemisorption can be stabilized by reaction with neighboring protonphilic radicals, like OH⁻. Furthermore, the geometries and associated energies of intermolecular hydrogen bonds between adsorbates on Cu(1 1 1) are also calculated. A model of the first layer of BTAH/BTA⁻ on Cu(1 1 1) surface is developed based on a hydrogen bond network structure.     

Promoting effect of low concentration of benzotriazole on the corrosion of Cu10Ni alloy in sulfide polluted salt water

The interaction of benzotriazole (BTAH) with the surface of a corroding copper–nickel alloy in a sulfide polluted salt solution reveals a change in its role from an inhibitor to a promoter of localized corrosion as its concentration changes. A concentration of BTAH ≥5 × 10⁻⁴ M inhibits the corrosion reaction in both the polluted and the unpolluted media. On the other hand, a concentration of 10⁻⁴ M BTAH promotes the localized corrosion of the alloy in the polluted medium while it acts as an inhibitor in the unpolluted salt solution. This finding is substantiated by measurements of mass loss and current transients and examination of the surface by SEM microscopy.     

CuInS2 thin films obtained through the annealing of chemically deposited In2S3-CuS thin films

In this work, we report the formation of CuInS₂ thin films on glass substrates by heating chemically deposited multilayers of copper sulfide (CuS) and indium sulfide (In₂S₃) at 300 and 350 °C in nitrogen atmosphere at 10 Torr. CIS thin films were prepared by varying the CuS layer thickness in the multilayers with indium sulfide. The XRD analysis showed that the crystallographic structure of the CuInS₂ (JCPDS 27-0159) is present on the deposited films. From the optical analysis it was estimated the band gap value for the CIS film (1.49 eV). The electrical conductivity varies from 3 × 10⁻⁸ to 3 Ω⁻¹ cm⁻¹ depending on the thickness of the CuS film. CIS films showed p-type conductivity.     

Bias voltage effect on the structure and property of chromium copper-diamond-like carbon multilayer films fabricated by cathodic arc plasma

Chromium copper-diamond-like carbon (Cr:Cu)-DLC films were deposited onto silicon and by cathodic arc evaporation process using chromium (Cr) and copper (Cu) target arc sources to provide Cr and Cu in the Me-DLC. Acetylene reactive gases were the carbon source and activated at 180 °C at 13 mTorr, and a substrate bias voltage was varied from −50 V to −200 V to provide the (Cr:Cu)-DLC structure. The structure, interface, and chemical bonding state of the produced film were analyzed by transmission electron microscope (TEM), IR Fourier transform (FTIR) spectra, and X-ray photoelectron spectroscopy (XPS). The results showed that the Cr-containing a-C:H/Cu coatings exhibited an amorphous layer of DLC:Cr layer and a crystalline layer of Cu multilayer structure. The profiles of sp³/sp² (XPS) ratios corresponded to the change of microhardness profile by varying the pressure of the negative DC bias voltage. These (Cr:Cu)-DLC coatings are promising materials for soft substrate protective coatings.     

Inhibition of copper corrosion by bis-(1,1′-benzotriazoly)-α,ω-diamide compounds in aerated sulfuric acid solution

Three kinds of novel corrosion inhibitors, bis-(1,1′-benzotriazoly)-α,ω-succinyldiamide (BSU), bis-(1,1′-benzotriazoly)-α,ω-adipoyldiamide (BAD), and bis-(1,1′-benzotriazoly)-α,ω-azelayldiamide (BAZ) were synthesized and certified by IR and ¹H NMR. Their corrosion inhibition effects for copper in 0.5 M H₂SO₄ were evaluated by weight-loss method. It shows that among the three compounds, only BSU behaves better compared with BTA. The inhibition efficiency (IE) increased with increasing BSU concentration to 85.2% at the 5 × 10⁻⁴ M level. Polarization studies showed that BSU suppressed both anodic and cathodic corrosion reactions. The minimum energy conformation of these compounds was obtained by MM2 force field program. The two benzotriazoly moieties in BSU molecule are more parallel than in other compounds. This is benefit to increase the inhibition effects of BSU.     

Formation and characterization of conductive thin layers of copper sulfide (CuxS) on the surface of polyethylene and polyamide by the use of higher polythionic acids

Layers of copper sulfide of varying composition and properties are formed on the surface of polyethylene and polyamide by a sorption-diffusion method using solutions of higher polythionic acids, H₂S_nO₆. The concentration of sulfur adsorbed-diffused into PE and PA depends on the degree of the acid sulfurity, n, the temperature of the solution and the period of the polymer treatment. The amount of copper in a sulfide (Cu_xS) layer formed after the sulfured polymer treatment with a solution of Cu(I-II) salt is strongly dependent on the concentration of sulfur in the PE and PA. By the chemical analysis of the obtained sulfide layers was determined that a value of x in the Cu_xS layers varies in the interval 1 < x < 2. The microscopic investigation of transverse sections of PE and PA samples with copper sulfide layers showed that the major part of copper sulfide is in the surface matrix of the polymer. X-ray diffraction studies of the Cu_xS layers obtained seven phases: with x = 2 (chalcocite), 1.9375 (djurleite), 1.8 (digenite), 1.75 (anilite), 1.12 (yarrowite), 1.06 (talnakhite) and 1 (covellite). The measurements of the electrical conductance of Cu_xS layers (0.1-4 S cm⁻²) showed that its value greatly depends on the conditions of PE and PA interaction with H₂S_nO₆ and of further interaction with Cu(I-II) salt solution, on the chemical and phase composition of the layer.     

Native oxidation of ultra high purity Cu bulk and thin films

The effect of microstructure and purity on the native oxidation of Cu was studied by using angle-resolved X-ray photoelectron spectroscopy (AR-XPS) and spectroscopic ellipsometry (SE). A high quality copper film prepared by ion beam deposition under a substrate bias voltage of −50 V (IBD Cu film at V_s = −50 V) showed an oxidation resistance as high as an ultra high purity copper (UHP Cu) bulk, whereas a Cu film deposited without substrate bias voltage (IBD Cu film at V_s = 0 V) showed lower oxidation resistance. The growth of Cu₂O layer on the UHP Cu bulk and both types of the films obeyed in principle a logarithmic rate law. However, the growth of oxide layer on the IBD Cu films at V_s = 0 and −50 V deviated upward from the logarithmic rate law after the exposure time of 320 and 800 h, respectively. The deviation from the logarithmic law is due to the formation of CuO on the Cu₂O layer after a critical time.     

Effect of indium doping in CdO thin films prepared by spray pyrolysis technique

Preparation of transparent and conducting indium doped CdO thin films by spray pyrolysis on glass substrate is reported for various concentration of indium (2-8 wt%) in the spray solution. The electrical, optical and structural properties of indium doped CdO films were investigated using different techniques such as Hall measurement, optical transmission, X-ray diffraction and scanning electron microscope. X-ray analysis shows that the undoped CdO films are preferentially orientated along (2 0 0) crystallographic direction. Increase of indium doping concentration increases the films packing density and reorient the crystallites along (1 1 1) plane. A minimum resistivity of 4.843×10⁻⁴ Ω cm and carrier concentration of 3.73×10²⁰ cm⁻³ with high transmittance in the range 300-1100 nm were achieved for 6 wt% indium doping. The band gap value increases with doping concentration and reaches a maximum of 2.72 eV for 6 wt% indium doping from 2.36 eV of that of undoped film. The minimum resistivity achieved in the present study is found to be the lowest among the reported values for In-doped CdO films prepared by spray pyrolysis method.     

Benzotriazole as an inhibitor of brass corrosion in chloride solution

The current research explores the formation of protective layers on copper, zinc and copper-zinc (Cu-10Zn and Cu-40Zn) alloys in chloride solution containing benzotriazole (BTAH), by use of electrochemical techniques, atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). Electrochemical reactions and surface products formed at the open circuit potential and as a function of the potential range are discussed. The addition of benzotriazole to aerated, near neutral 0.5 M NaCl solution affects the dissolution of copper, zinc, Cu-10Zn and Cu-40Zn alloys. The research also compares the inhibition efficiency and Gibbs adsorption energies of the investigated process. Benzotriazole, generally known as an inhibitor of copper corrosion is also shown to be an efficient inhibitor for copper-zinc alloys and zinc metal. The surface layer formed on alloys in BTAH-inhibited solution comprised both oxide and polymer components, namely Cu₂O and ZnO oxides, and Cu(I)-BTA and Zn(II)-BTA polymers. The formation of this mixed copper-zinc oxide polymer surface film provides an effective barrier against corrosion of both metal components in chloride solution.     

Deposition of nanostructured crystalline and corrosion resistant alumina film on bell metal at low temperature by rf magnetron sputtering

Aluminium oxide films deposited by rf magnetron sputtering for protective coatings have been investigated. The alumina films are found to exhibit grainy surface microstructure. The grain size, structure and density depend on different system parameters such as argon and/or oxygen flow rate and applied rf power etc. The effect of transition of the discharge from metallic to reactive mode on the surface characteristics of the alumina film is studied. X-ray diffractometry reveals that in poisoned mode of sputtering and under optimized power and pressure, crystalline alumina film can be grown. Different system conditions are optimized for corrosion resistant aluminium oxide films with good adhesion properties. Nanostructured alumina film is obtained at lower pressure (8 × 10⁻⁴ to 9 × 10⁻⁴ Torr) by rf reactive magnetron sputtering.     

Laser sintering of Cu paste film printed on polyimide substrate

We here show that highly conductive copper films are obtainable from Cu paste by laser sintering. The Cu paste synthesized using an organo-metallic compound was screen-printed onto polyimide substrate and the printed films were scanned by an ultraviolet laser beam at 355 nm under nitrogen atmosphere. Very compact microstructure was observed throughout the whole thickness and the sintered films were mechanically robust. Although Cu is known susceptible to oxidation, no Cu oxides were incorporated into the film during laser sintering. An electrical resistivity of 1.86 × 10⁻⁵ Ω cm was obtained. This resistivity is several orders of magnitude lower than those reported for the copper nanoparticle paste thermally sintered under N₂ or H₂ atmosphere.     

Use of the direct negative Cu ion beam deposition for the control of the properties of Cu thin film

Direct metal ion beam deposition (DMIBD) technique for Cu thin film metallization is characterized. With suitable operating conditions, secondary Cu⁻ ion yield, ion/atom arrival rate ratio, ion beam energy spreads were optimized at 15%, 0.3, and 10%, respectively.After optimization of DMIBD system, the effect of Cu ion beam energy on the resistivity, adhesion strength, and surface morphology of Cu thin film was investigated. TEM micrograph shows that the film prepared at 75 eV was polycrystalline, while the film prepared at 0 eV was vertical columnar structure.As ion beam energy is increased from 25 to 75 eV, the resistivity is decreased from 6.21 to 2.09 μΩ cm, while the critical load to cause adhesion failure was increased to about 13 N at 200 eV, which is four-times higher that that of 25 eV.     

Transparent conducting molybdenum-doped zinc oxide films deposited by RF magnetron sputtering

A new transparent conducting oxide (TCO) film with low resistivity and high transmittance in the visible range, molybdenum-doped zinc oxide (MZO), was successfully prepared by RF magnetron sputtering method on glass substrates at room temperature. The structural, electrical, and optical properties as a function of film thickness were investigated. All the samples have a preferred orientation with the (0 0 2) planes parallel to the substrates. The resistivity initially decreases and then shows an increase with the increase of the film thickness. When the thickness is 400 nm, the film has its best crystallinity and lowest resistivity 9.2 × 10⁻⁴ Ω cm with a Hall mobility of 30 cm² V⁻¹ s⁻¹ and a carrier concentration of 2.3 × 10²⁰ cm⁻³. The average transmittance in the visible range exceeds 84% for all thickness films.     

Copper sulfide coated polysulfone films

The modification of polysulfone surface was used to obtain effective interactions between an organic polymeric surface and an inorganic specie. A previous treatment of the polymer surface with modifiers is required in order to provide adherence. Our objective was the synthesis and the surface characterization of copper sulfide coated polysulfone (CuS-PSf) films. SEM micrographs showed a homogeneous distribution of copper sulfide, which contributes to increasing electrical conductivity. X-ray analysis showed a decrease in copper sulfide particles (covellite porcelain) when compared with other polymeric composites prepared under similar conditions. The measured surface conductivity of the CuS-PSf films was higher than those of other similar systems, ca. 800 S cm⁻¹.     

Pulsed electron beam deposition of highly oriented thin films of polytetrafluoroethylene

Thin films of polytetrafluoroethylene (PTFE) were deposited by pulsed electron deposition (PED) technique. The transmission electron microscopy (TEM) image of the RT fabricated (20 Å thick) film on carbon coated copper grid shows crystalline nature. Infrared spectra show one to one correspondence between PED ablated film and the PTFE bulk target. The asymmetrical and symmetrical -CF₂- stretching modes were observed at 1220 and 1156 cm⁻¹, respectively. The -CF₂- wagging and bending modes occur at 644 and 512 cm⁻¹, respectively. X-ray diffraction patterns of the film deposited at room temperature (RT) show oriented film along (1 0 0) plane of hexagonal structure and the crystalline nature is retained up to 300 °C on vacuum annealing. The room temperature fabricated film shows smooth and pin hole free surface whereas post-annealing brings discontinuity, roughness and pin holes.     

Photoluminescence and Raman scattering of Cu-doped ZnO films prepared by magnetron sputtering

The Cu-doped ZnO films were prepared by direct current reactive magnetron sputtering using a zinc target with various Cu-chips attached. The influences of Cu-doping on the microstructure, photoluminescence, and Raman scattering of ZnO films were systematically investigated. The results indicate that ZnO films doped with moderate Cu dopant (2.0-4.4 at.%) can obtain wurtzite structure with strong c-axis orientation. The near band edge (NBE) emission of ZnO film can be enhanced by Cu dopant with a concentration of 2.0 at.% and quench quickly with further increase of doping concentration. Two additional modes at about 230 and 575 cm⁻¹, which could be induced by Cu dopant, can be observed in Raman spectra of the Cu-doped ZnO films.     

A study on the wet etching behavior of AZO (ZnO:Al) transparent conducting film

This paper studies the wet etching behavior of AZO (ZnO:Al) transparent conducting film with tetramethylammonium hydroxide (TMAH). The optimum optoelectronic film is prepared first using designated RF power, film thickness and controlled annealing heat treatment parameters. The AZO film is then etched using TMAH etchant and AZ4620 photoresist with controlled etchant concentration and temperature to examine the etching process effect on the AZO film optoelectronic properties. The experimental results show TMAH:H₂O = 2.38:97.62 under 45 °C at the average etch rate of 22 nm/min as the preferred parameters. The activation energy drops as the TMAH concentration rises, while the etch rate increases along with the increase in TMAH concentration and temperature. After lithography, etching and photoresist removal, the conductivity of AZO film dramatically drops from 2.4 × 10⁻³ Ω cm to 3.0 × 10⁻³ Ω cm, while its transmittance decreases from 89% to 83%. This is due to the poor chemical stability of AZO film against AZ4620 photoresist, leading to an increase in surface roughness. In the photoresist postbaking process, carbon atoms diffused within the AZO film produce poor crystallinity. The slight decreases in zinc and aluminum in the thin film causes a carrier concentration change, which affect the AZO film optoelectronic properties.     

Van der Pauw resistivity measurements on evaporated thin films of cadmium arsenide, Cd3As2

Cadmium arsenide is a II-V semiconductor, exhibiting n-type intrinsic conductivity with high mobility and narrow bandgap. It is deposited by thermal evaporation, and has shown the Schottky and Poole-Frenkel effects at high electric fields, but requires further electrical characterisation. This has now been extended to low-field van der Pauw lateral resistivity measurements on films of thickness up to 1.5 μm. Resistivity was observed to decrease with increasing film thickness up to 0.5 μm from about 3 × 10⁻³ Ω m to 10⁻⁵ Ω m, where the crystalline granular size increases with film thickness. This decrease in resistivity was attributed to a decrease in grain boundary scattering and increased mobility. Substrate temperature during deposition also influenced the resistivity, which decreased from around 10⁻⁴ Ω m to (10⁻⁵ to 10⁻⁶) Ω m for an increase in substrate deposition temperature from 300 K to 423 K. This behaviour appears to result from varying grain sizes and ratios of crystalline to amorphous material. Resistivity decreased with deposition rate, reaching a minimum value at about 1.5 nm s⁻¹, before slowly increasing again at higher rates. It was concluded that this resulted from a dependence of the film stoichiometry on deposition rate. The dependence of resistivity on temperature indicates that intercrystalline barriers dominate the conductivity at higher temperatures, with a hopping conduction process at low temperatures.     

Potential dependence of cuprous/cupric duplex film growth on copper electrode in alkaline media

The duplex oxide film potentiostatically formed on copper in concentrated alkaline media has been investigated by XRD, XPS, negative-going voltammetry and cathodic chronopotentiometry. The interfacial capacity was also measured using fast triangular voltage method under quasi-stationary condition. The obvious differences in the thickness, composition, passivation degree and capacitance behavior were observed between the duplex film formed in lower potential region (−0.13 to 0.18 V versus Hg|HgO electrode with the same solution as the electrolyte) and that formed in higher potential region (0.18-0.60 V). Cuprous oxides could be formed and exist stably in the inner layer in the both potential regions, and three cupric species, soluble ions and Cu(OH)₂ and CuO, could be independently produced from the direct oxidation of metal copper, as indicated by three pairs of redox voltammetric peaks. One of the oxidation peaks appeared only after the scan was reversed from high potential and could be attributed to CuO formation upon the pre-accumulation of O²⁻ ions within the film under high anodic potentials. A new mechanism for the film growth on the investigated time scale from 1 to 30 min is proposed, that is, the growth of the duplex film in the lower potential region takes place at the film|solution interface to form a thick Cu(OH)₂ outer layer by field-assisted transfer of Cu²⁺ ions through the film to solution, whereas the film in the higher potential region grows depressingly and slowly at the metal|film interface to form Cu₂O and less CuO by the transfer of O²⁻ ions through the film to electrode.