Kinds Of Films Research Articles

PHOTOABSORPTION OF COMPLEX THIN FILMS OF NOBLE METAL PARTICLES EMBEDDED IN MATRIX (Au-BaO,Cu-BaO)

In this paper the ultraviolet—visible photoabsorption spectrum of the complex thin films of noble metal (Au,Cu) particles embedded in BaO matrix is measured.The absorption spectra of the two kinds of films are quite different.There are surface plasmon mode and band transition absorption in the spectrum of the Au-BaO thin film.However,several peaks appear in the spectrum of the Cu-BaO thin film,because Cu exists as very small particles in the matrix.The absorption spectrum is dependent on the metal content.

Experimental Verification of Optimum Density Obtained from Psychophysical Gradients

The optimum density is the density at which the best detectability is attained. The theoretical optimum density was obtained using psychophysical gradients (psychophysically modified gradients). The experimental optimum densities obtained by a visual experiment were compared with the theoretical optimum densities for radiographs of three types of object: two periodic fabrics having spatial frequencies oft and 3 mm-1 and a step-edge fabric using two kinds of film. The experimental optimum densities coincided in all cases with the theoretical optimum densities at which psychophysical gradient values reached maxima. The psychophysical gradient ivas confirmed to be useful for obtaining the optimum density.

The changing generic location of crime in film: a content analysis of film synopses, 1945-1991

Is the number of films containing crime increasing? If so, for which kinds of films? Using a sample of synopses for all films released in Britain between 1945 and 1991, we identified shifts in the major film genres and their proportion of crime contents. The overall proportion of crime films and the proportion of crime content in all film genres has remained constant. This masks underlying differences, however. Content analysis revealed which genres, including those with both high and low crime content, are rising or falling in popularity. It also revealed that for some genres, the proportion of films containing crime is rising. No differences were found between British and U.S. films in terms of proportion of crime content by genre. This historical content analysis provides an overview of trends in the inclusion of crime in film. These trends offer a broader context for the interpretation of more detailed analyses of single films. We discuss implications for the audience's expectations of films.

Structural and morphological studies on Langmuir-Blodgett films of pheophytine a by ultraviolet–visible and infrared spectroscopies and atomic force microscopy

The structure concerning the molecular aggregation in Langmuir-Blodgett (LB) films of pheophytine a (Phe- a) has been studied by ultraviolet–visible (UV–Vis) and infrared (IR) spectroscopies and their morphology has been delineated by atomic force microscopy (AFM). UV–Vis spectra were measured for a chloroform (CHCl 3) solution of Phe- a, cast film from the CHCl 3 solution and six-layer LB films of Phe- a prepared in air and argon (Ar) atmospheres. A comparison of these UV–Vis spectra indicates the existence of two kinds of aggregates of Phe- a in the cast and LB films. One has a Qy band at 683 nm and another has a corresponding band at 700 nm. Soret bands of the cast and LB films also show a marked broadening. It is suggested from the UV–Vis measurements that the LB film prepared in the Ar atmosphere includes the aggregate with the 700 nm band at the highest ratio among the three kinds of films. On the other hand, the IR spectra of the solution, and cast and LB films resemble each other, suggesting that Phe- a exists in a monomer in them. Therefore, it seems that the aggregates are composed of stacked Phe- a monomers with a π– π interaction. AFM images for the LB films of Phe- a prepared in the air and Ar atmosphere reveal that they have very smooth and flat surface.

The Changing Generic Location of Crime in Film: A Content Analysis of Film Synopses, 1945–1991

Is the number of films containing crime increasing? If so, for which kinds of films? Using a sample of synopses for all films released in Britain between 1945 and 1991 we identify shifts in the major film genres and their proportion of crime contents. The overall proportion of crime films remains constant, as does the proportion of crime contents in all film genres. But this masks underlying differences. Content analysis reveals which genres, including those with both high and low crime contents, are rising or falling in popularity. It also reveals that for some genres, the proportion of films containing crime is rising. No differences were found between British and American films in terms of proportion of crime contents by genre. This historical content analysis provides an overview of trends in the inclusion of crime in film. These trends offer a broader context for the interpretation of more detailed analyses of single films. The implications for the audience's expectations of films are discussed.

FORMATION AND MICROSTRUCTURE OF (105)-ORIENTED EPITAXIAL THIN FILMS OF YBa2Cu3O7-δ

The formation and microstructure of the YBa 2 Cu 3 O 7-δ thin films grown on (305) SrTiO 3 substrates have been studied by means of transmission electron microscopy, X-ray diffraction analysis and scanning electron microscopy. YBa 2 Cu 3 O 7-δ was epitaxially grown on the stepped surface of such tilted substrates with an angle of 31° between its c axis and the substrate surface normal, forming the (105)-oriented films. A common feature of this kind of films is that small antidomains are nucleated in the initial growing stage. However, the further growth of these antidomains is depressed by the growth of YBa 2 Cu 3 O 7-δ with the desired orientation, leading to the formation of a single domain film. The surface of the (105) YBa 2 Cu 3 O 7-δ films is significantly rougher than that of c axis films but smoother than that of some other tilted films. Strong anisotropy of the transport properties has also been found in the [010] and [Formula: see text] directions of the (105) YBa 2 Cu 3 O 7-δ films.

Religious conflict, popular culture and the troubled spectators of recent Indian film

While detailed studies have been devoted to the visual cultures of the Western world, comparatively little attention has been paid to the circulation and popular consumption of images in India. It would be a mistake simply to adapt Western theories of film spectatorship to the Indian situation, for these fail to account adequately for the heterogeneity of film audiences or the modes of address film‐makers adopt to appeal to specialised constituencies of viewers. The problems of defining Indian spectatorship have been brought into sharp focus by the rapid spread of ‘reality television’ following the broadcasting of the fratricidal communal conflicts of 1992–1993. Film‐makers, whether they sought a mass audience within India, packaged Indian social realities for Western viewers or appealed to the leftist sympathies of an educated elite, began to turn to the traumas of recent history for their subject matter. The kinds of films they have made illustrate the diversity of Indian spectatorship as well as the continuing vitality of the cinema as a medium of cultural exchange and social transformation.

The preparation, characterization of amorphous Cu–TCNQ film with a low degree of charge-transfer (DCT) and its electric switching properties

Two sorts of Cu–TCNQ films were prepared and characterized. One kind of film is amorphous, exhibiting novel electrical switching effects. The device configuration is a sandwich structure, typically, Al/amorphous Cu–TCNQ thin film/Cu. Films are grown on a Cu substrate by immersion in saturated malononitrile solutions of TCNQ (7,7,8,8-tetracyanoquinodimethane) at 50∼80 °C. The degree of charge transfer (DCT) in this film is estimated at 0.41 according to the position of the IR absorption line of the CN vibration. The current–voltage ( I– V) characteristics reveal an abrupt decrease of the impedance from 2.4 KΩ to 6Ω (for a typical sample) at a field strength about 4×10 3 V cm −1 for a 1 μm thick film. The low impedance memory state can be erased by the application of large current in either direction. Moreover, the device switches to the low impedance state again when the field strength across the film is decreased below 2×10 4 V cm −1. The device is stable over a long period of time and has a life time of roughly 50 switching cycles. A possible switching mechanism is proposed.

Effect of Hydrostatic Pressure on the Resistivity of n- and p-Type Polycrystalline InSb Thin Films

The effect of hydrostatic pressure on the resistivity of InSb thin films with acceptor/donor concentrations in the range 2 x 10 16 to 2 x 10 19 cm -3 is investigated at pressure up to 0.8 GPa. Two kinds of films are studied: as vapour grown low mobility (LM) and melt regrown high mobility (HM) films. The magnitude of the pressure effect in the n-type HM films is close to that in bulk InSb ; whereas the magnitude of the effect in the LM films is considerably higher. Moreover, the resistance of the LM films shows an untypical parabolic dependence on pressure. The parabolic dependence is enhanced at low temperatures. As far as we know such a strong dependence of the resistance on pressure has not yet been observed in semiconductor materials. The LM InSb films appear to be a very promising material for high pressure gauges, especially for cryogenic applications. The most promising LM InSb films for cryogenic pressure sensors are those with electron concentrations between 2 x 10 17 and 5 x 10 18 cm -3 .

Formation of YBa 2Cu 3O 7 tetragonal phase by rapid cooling of thin films grown by cathodic sputtering

YBa 2Cu 3O 7−δ (YBaCuO) thin films were prepared in situ by cathodic sputtering of stoichiometric target onto LaAlO 3 or MgO single crystal substrates. After deposition some samples were cooled down quickly (hundreds degrees/min) till room temperature under 0.35 mbar or 1 bar of O 2, in order to preserve the original oxygen content and the structure of the films during the in situ growth. Reference samples were cooled down slowly (∼ 3°C/min, 1 bar of O 2), at optimized conditions. The composition, electrical and magnetic properties and microstructure of YBaCuO films were studied ex situ at room temperature. Both slowly and rapidly cooled samples at 1 bar of O 2 show good physical properties with values of T c (ϱ = 0) ≂ 87 K , surface resistance R s( measured at 77 K, 10 GHz) ≂ 1 mΩ and J c (T = 5 K, zero field) ≂ × 10 7 A/cm 2 . The rapidly cooled sample at low oxygen pressure shows high T c value but significant degradation of R s is observed. Our direct oxygen content measurements using recently developed Ion Beam Analysis (IBA) techniques show that both kind of films are fully oxygenaaed (O 7± 0.3) YBaCuO compounds. The combination of X-ray Diffraction (XRD) and Transmission Electron Microscopy (TEM) measurements indicates the majority presence, in the case of the rapidly cooled films, of a disordered tetragonal phase, with lattice parameters a = b = 3.86 A ̊ and c = 11.690 A ̊ , whereas for the slowly cooled samples the dominant structure is orthorhombic, with a = 3.82 A ̊ , b = 3.88 A ̊ and c = 11.686 A ̊ . It is concluded that fully oxygenated YBaCuO tetragonal phase is growing during cathodic deposition.

High resolution X-ray diffraction mapping studies on the domain structure of LaAlO 3 single crystal substrates and its influence on SrTiO 3 film growth

High resolution X-ray diffraction mapping studies have been done on 001-oriented LaAlO 3 substrates and epitaxial 001-oriented SrTiO 3 thin films grown on the LaAlO 3. Using high resolution ω-ω 2θ reciprocal space mapping over the 002 peak, the lattice constant of LaAlO 3 could be accurately determined; however, it was not possible to determine the small splitting of the 002 peak due to the different twin domains. This is due to the poor resolution, inherent from the diffractometer design, for planes perpendicular to the diffraction plane. The pole plot method also makes use of the resolution perpendicular to the diffraction plane and will therefore not resolve the domain either. However, ω-ø mapping has been successfully used to resolve the domain distribution and angles between the domains since it scans the diffraction space in a plane parallel to the sample surface and it has high resolution along the ω direction. It was found that the LaAlO 3 usually contains four domains with four-fold twinning symmetry. The angular separations of the domains were 0.177°, 0.177° and 0.253°. Annealing the sample showed to have a detwinning effect sometimes resulting in a single domain sample. To investigate the influence of the domain structure on the growth of SrTiO 3 films, two kinds of films were studied. For stoichiometric SrTiO 3 film the domain structure of the substrate was exactly copied into the film as revealed by the ω-ω 2θ map and ω-ø maps. On the other hand Sr-deficient film exhibited a large degree of mosaicity and the resulting peak broadening overwhelmed the splitting due to domains.

Ion-Beam Bombarding Effects on Deposition of Carbon Nitride Films by Laser Ablation

In order to obtain high quality carbon nitride films, x-ray photoelectron spectroscopy and Raman spectrum were used to analyze several kinds of film: (a) laser-ablated amorphous carbon (a-C) films, (b) a-C films after a 1 keV nitrogen ion beam bombardment. (c) carbon nitride (CNx) films synthesized by ablation assisted with ion beam bombardment, (d) CNx films after a 50 eV nitrogen ion beam bombardment, and (e) CNx films after 1 keV nitrogen ion beam bombardment. The comparison among these films showed that the concurrent deposition of CNx films by ablation and a nitrogen ion beam should be better than the post-treatment of a-C films by nitrogen ion beam bombardment. In the case of concurrent deposited CNx films, a post-treatment by a nitrogen ion beam bombardment with an appropriate energy (possibly less than 1 keV) was proposed to improve the ratio of C-N binding structures in the deposited films.

Surface inspection by an optical triangulation method

A noncontact optical microtopographer based on an active, discrete triangulation procedure has been under development for some time at the physics department of the University of Minho. Our experi- ence has shown that this kind of triangulation-based surface inspection system can be applied, not only to long-distance range sensing, but also to smaller samples or other surfaces with height resolutions that can go down to the submicron range. In our system, the topographic information is obtained from the horizontal shift of the bright spot created by an oblique collimated light beam on a surface when it is displaced vertically. A laser beam is focused onto a small, diffraction-limited spot on the surface and is made to scan it over the desired region. The horizontal position of the bright spot is perpendicularly imaged onto a linescan cam- era and the information on the individual detectors that are activated, above a certain controllable intensity threshold level, is used to compute the corresponding horizontal spot's shift on the reference plane. Thus we can compute the distance between the surface and a reference plane at each sampled point. A map of the surface topography can then be built and statistical surface characterization parameters may be calculated. Our versatile laboratory setups have been used for different inspection tasks such as thickness measurements and relief mapping of different kinds of films (polyethylene, thin sputtered copper, tin dioxide and silver films) and several kinds of fabrics, and roughness measure and topo- graphic inspection of polyethylene molds and graphite samples. In this communication we briefly describe our method. The current configura- tion of our laboratory setup is described. A hand-held version of our system and also the setup for long-distance dimensional assessments are briefly presented. © 1996 Society of Photo-Optical Instrumentation Engineers. Subject terms: rough surfaces; microtopography; electro-optical sensors; rough- ness.

Effect of sputtering atmosphere on superconductivity of La 2−xSr xCu 1−yO 4 thin films

c-axis oriented La 2−xSr xCu 1−yO 4 (x∼0.15) films were grown by dc magnetron sputtering on Y-stabilized ZrO 2, SrTiO 3 and LaAlO 3 substrates. It was found that the zero resistance temperature, T c0, and the lattice parameters of the films are strongly dependent on the sputtering O 2:Ar gas ratios. A strong thickness dependence of T c0 was also found in this kind of film, T c0 of 22 K was obtained on ∼2000 Å thickness film grown on LaAlO 3 substrate. The O 2:Ar ratios primarily modify the copper content, rather than the oxygen content of the films. The variation of the Cu content of the films strongly dominates the seperconductivity of the films.

The use of films to simulate age-related declines in yellow vision

One of characteristics of normal age-related vision losses depends on yellow-intensity in the lens of the eye. (1) We investigated discrimination between seven intensities of yellow in 303 elderly people aged from late 60s to early 90s. The results demonstrated that the failures of vision increase with age, and the losses depend on yellow intensity. (2) We got a yellow index (YI) from different Y-intensity color charts used in (I) above, covering 12 kinds of marketable yellow films, and selected two kinds of films which match (YI) original color charts, corresponding to 53% or 89% of Y intensity. (3) Finally, we judged that all of these colors' xy-chromaticities with or without the two films, were exactly on the unique-yellow line in the diagram, which means a pure yellow, not mixed. (4) Then, these two films could simulate each of the mid-level or high-level Y intensity, respectively, in age-related vision. (5) We analyzed changes of all kinds of colors (220) in xy-chromaticity diagrams and obtained mean changing distances from every original chromatogram compared to the others. These data would be useful for architects or designers to design cities or buildings for use by the elderly.

SiO 2 film formation at room temperature by gas cluster ion beam oxidation

High quality SiO 2 film of thicknesses less than 11 nm were formed on Si substrate surfaces at room temperature by irradiation with O 2 and CO 2 cluster ions. The acceleration voltages were in the range of 5–10 kV. The minimum cluster size was 250 molecules, thus the maximum energy per molecule was less than 40 eV. These SiO 2 films which were formed had a stoichiometric composition, smooth interfaces with Si substrates and low carbon content. The results indicate a high chemical reactivity of gas cluster ions. Thus, the gas cluster ion beam technique has a potential for the formation of various kinds of films at low temperatures.

Comparative impedance spectroscopy study of rutile and anatase Tio 2 film electrodes

The purpose of this work was a comparative electrochemical impedance analysis of the titanium dioxide-solution interface for two kinds of thin film samples consisting respectively of anatase and rutile. These kind of films, frequently used in photoelectrochemical experiments, have recently been the subject of detailed physical studies showing important differences in electrical properties between those two forms of TiO 2. The EIS measurements were carried out over a wide frequency range (from 0.03 Hz to 10 kHz), analysing the whole spectrum.

Ion-beam-assisted deposition of nonhydrogenated a-Si:C films

Amorphous silicon carbide (a-Si:C) films were prepared by low-energy ion-beam-assisted deposition (IBAD) in an attempt to remove structural defects in the "lattice" and improve the electrical characteristics of the film. The ion beam was generated by electron cyclotron resonance from an ultra-high-purity argon plasma. The deposition environment was first evacuated to a very high vacuum to eliminate all but trace amounts of water vapour and other gases so that improvements in the electrical and (or) structural properties of the film would be attributable to the influence of the densification by ion bombardment and not to contaminants. The IBAD process does improve the film characteristics by reducing the density of localized states at the Fermi level and the porosity of the film. However, even though these films have the best electrical characteristics obtained thus far for these kind of films, none of them exhibited device quality and none were observed to be photoconducting. A large density (≈1 at.%) of implanted argon atoms may be limiting the reduction in the defect density that might otherwise be achievable.

Refractive Index of Uniaxially Stretched Poly(ethylene terephthalate) Film at Microwave Frequencies

Refractive indices of uniaxially stretched poly(ethylene terephthalate) films with 9–10% crystallinity were determined at microwave frequencies. An empirical formula nMW=0.0508+1.0681 nOPT was derived, with a correlation coefficient of 0.998, where nMW and nOPT denote the refractive indices at 4.0 GHz and 5.09×1014 Hz (589 nm wavelength), respectively. The coefficient of 1.0681 between nMW and nOPT was smaller than that of 1.3561 in the previously determined empirical formula for biaxially stretched poly(ethylene terephthalate) films with 35% crystallinity. Such a difference in the coefficient may be ascribed to the difference in crystallinity between two kinds of films. It was found that nMW decreased when the frequency increased from 4.0 GHz to 12.2 GHz but was distinctly higher than nOPT and appeared to approach nOPT.

高周波大振幅励磁における軟磁性薄膜のパーミアンス

We measured the permeance of Cu-Mo-Ni-Fe film and Co-Zr-Nb film up to 5 Oe and up to 10 MHz along the hard and easy axes of magnetization, using the figure-of-eight coil method, with a new three-turn separated type of Helmholtz coil. The permeance of Cu-Mo-Ni-Fe film and Co-ZrNb film along the hard axis of magnetization changed when the amplitude of the magnetic field exceeded the anisotropy field of each film. The permeance along the easy axis of magnetization depended on the kind of film. The perrneance of Cu-Mo-Ni-Fe film along the easy axis of magnetization changed when the amplitude of the magnetic field exceeded the corresponding ac coercive force.