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Influence of residual stress and film thickness on crystallographic orientation in Al thin films deposited by bias sputtering
No full textAl thin films with various residual stress and him thickness were deposited by bias sputtering. Residual stress and relative intensity of the (200) to (111): plane of Al thin films were measured by x-ray diffraction. When film thickness is fixed at 1 mu m below the residual stress of similar to 80 MPa, AZ thin films have a (111) orientation, but above this stress, a (100) orientation. If Al thin films are in the high residual stress of similar to 145 MPa, crystallographic orientation changes to a (100) from a (111) orientation as film thickness increases to 2 mu m from 1 mu m. However, Al thin films with the residual stress of similar to 25 MPa have a (111) orientation regardless of film thickness. Total energy for Al thin films of a (100) and a (111) orientation was calculated as a function of residual stress and film thickness. These experimental results could be explained by the minimization of the sum of strain energy and surface energy in the films. (C) 1998 American Vacuum Society.[S0734-2101(98)04106-2]
ORIGIN OF INTRINSIC STRESS IN Y2O3 FILMS DEPOSITED BY REACTIVE SPUTTERING
No full textY2O3 thin films were deposited by reactive sputtering of an Y target in an Ar and O-2 gas mixture. Intrinsic stresses and the Ar content in the films were measured by the sine square psi method of x-ray diffraction and wavelength dispersive spectrometer, respectively. At low working pressures the films had high compressive stresses. As working pressure increased, compressive stress was relaxed. Ar content was high in the film that had high compressive stress. After annealing of the films at 700 degrees C, the compressive stress was largely relaxed but the Ar content remained unchanged. These results clearly showed that compressive stress in Y2O3 films was not caused by Ar entrapment as an impurity but by Ar bombardment. Intrinsic stress was almost independent of the O-2/Ar flow ratio. showing that O bombardment was equal to Ar bombardment in affecting the intrinsic stress in Y2O3 films. The independence of intrinsic stress with the O-2/Ar flow ratio was explained by the concept of M(i)(1/2){[M(i) cos theta+/-(M(t)(2) - M(i)(2) sin(2) theta)(1/2)]/(M(i) + M(t))} instead of the M(i)/M(i) ratio, where M(t) is the atomic mass of the target material, M(i) is the atomic mass of the sputtering gas, and theta is the scattering angle. (C) 1995 American Vacuum Society
Intrinsic stress and its relaxation in diamond film deposited by hot filament chemical vapor deposition
No full textIntrinsic stress in diamond films fabricated by hot filament chemical vapor deposition was investigated as a function of deposition temperature, CH4 concentration, and positive bias voltage. The intrinsic stress in the diamond film was tensile between 810 and 980 degrees C. The minimum tensile stress existed at 880 degrees C. The relationship between tensile intrinsic stress and deposition temperature was explained by the nondiamond phase and crystallite size. The tensile intrinsic stress decreased almost linearly with CH4 concentration in the range of 0.4%-1.2%. Applying +50 V to the Si substrate, the tensile intrinsic stress was reduced from 2.4 to 0.7 GPa without any change in the quality of the diamond film. This relaxation was attributed to the beta-SiC buffer layer formed by electron bombardment onto the Si substrate. (C) 1996 American Vacuum Society
Prediction of Bond Strength and Thermal Fatigue Characteristic of Plasma Sprayed Thermal Barrier Coatings by Finite Element Method
No full textInfluence of film density on residual stress and resistivity for Cu thin films deposited by bias sputtering
No full textCu thin films were deposited by bias sputtering and the film density was measured by grazing incidence X-ray reflectivity. The influence of the experimentally measured film density on residual stress and resistivity, which previously few studies reported on, was investigated. Without bias voltage, the relative film density was low and the tensile stress was high. With increasing bias voltage, the tensile stress decreased and saturated to nearly zero at a bias voltage of -100 V, while the film density increased and saturated to nearly bulk value at a bias voltage of -100 V. These results were consistent with those from previously reported molecular dynamic simulations. From the consideration of the Morse potential for relatively dense films, it was possible that tensile stress decreased as the film density increased. The resistivity is high in Cu thin films deposited without bias voltage. With increasing bias voltage, the resistivity decreased and saturated to nearly bulk value at a bias voltage of -100 V. The resistivity is thought to be influenced by the him density. (C) 2000 Elsevier Science S.A. All rights reserved.This work was supported by the Korea Science and Engineering Foundation (grant no. 985-0800-019-2)
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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