Effect of Substrate Constraint on Stress-Induced Deformation Mechanism of Tungsten Thin Film

2010 ◽  
Vol 89-91 ◽  
pp. 539-544
Author(s):  
H.L. Sun ◽  
Fei Ma ◽  
Zhong Xiao Song ◽  
Yan Huai Li ◽  
Ke Wei Xu
Keyword(s):  
Thin Films ◽  
Residual Stress ◽  
Morphological Characteristics ◽  
Point Of View ◽  
Out Of Plane ◽  
Typical Morphology ◽  
Deformation Behaviors ◽  
Stress States ◽  
Localized Plastic Deformation ◽  
Substrate Constraint

The deformation process of sputtered tungsten films were investigated according to the morphological characteristics and residual stress analysis. Results show that there are four characteristics depending on the substrates and stress state. For thin films on polyimide, the localized plastic deformation is mediated by the alignment of grain boundaries in the case of tension or line bulges in the case of compression. It results from both in-plane and out-of-plane grain rotation. For thin films on silicon substrate, wedge cracks in the case of tension or regular hillocks in the case of compression become the typical morphology. From this point of view, the deformation behaviors of films depended on the substrate constraint and residual stress states.

Residual Stress of Aluminum Thin Films Sputtered on Silicon Wafers Measured by X-Ray Diffraction

1995 ◽  
Vol 39 ◽  
pp. 267-279
Author(s):  
Keisuke Tanaka ◽  
Keisaku Ishihara ◽  
Yoshiaki Akiniwa
Keyword(s):  
Thin Films ◽  
Residual Stress ◽  
Stress Measurement ◽  
Biaxial Tension ◽  
Film Surface ◽  
Fiber Texture ◽  
Fiber Axis ◽  
X Ray ◽  
Plane Normal ◽  
Out Of Plane

A new method of the X-ray stress measurement was proposed for measuring the residual stress in Al thin films having the [111] fiber texture with the fiber axis perpendicular to the film surface. The strain was measured from Al 222 and 311 diffractions obtained by Cr-Kα radiation. The values of in-plane residual stresses σ11, σ22 and σ12, and out-of-plane normal residual stress, σ33 were determined from the measured strains by using the fundamental formulae derived on the basis of Reuss and Voigt models. The measured residual stress in the thin films was nearly equi-biaxial tension. The magnitude of the tensile residual stress decreased with increasing film thickness.

Reaction-mediated texturing of barium ferrite magnetic thin films on ZnO underlayer

1995 ◽  
Vol 10 (9) ◽  
pp. 2343-2349 ◽  
Author(s):  
Jinshan Li ◽  
Robert Sinclair ◽  
Stephen S. Rosenblum ◽  
Hidetaka Hayashi
Keyword(s):  
Thin Films ◽  
Transition Layer ◽  
Barium Ferrite ◽  
Lattice Mismatch ◽  
Magnetic Thin Films ◽  
Point Of View ◽  
Ex Situ ◽  
Si Substrates ◽  
Out Of Plane ◽  
Facing Target Sputtering

Using facing target sputtering, crystalline magnetoplumbite-type barium ferrite (BaFe12O19 or BaM) thin films have been prepared in situ at a substrate temperature of 640 °C without postdeposition annealing. Using our facing target sputtering system, BaM thin films grow randomly if they are directly deposited onto Si or thermally oxidized Si substrates. However, deposited onto a sputtered ZnO layer (∼230 Å) on Si substrates, BaM thin films show excellent c-axis out-of-plane texture with a 0.2°c-axis dispersion angle, as indicated by x-ray diffraction (XRD). Cross-section transmission electron microscopy (XTEM) reveals that the textured films epitaxially grow on a transition layer, which is formed between BaM and ZnO. No direct epitaxial relation between BaM and ZnO was observed. This transition layer is identified by TEM and XRD as ZnFe2O4, which, from a structure point of view, reduces the lattice mismatch between BaM and ZnO, and also enhances the c-axis out-of-plane epitaxial growth. ZnFe2O4 is a reaction product of BaM and ZnO, as indicated by both TEM and XRD. After ex situ annealing the film in air at 800 °C, the ZnFe2O4 layer becomes thicker at the expense of BaM and ZnO. The lattice parameters of both BaM and ZnO decreased as annealing time increased.

The Effect of Residual Stresses on the Deformation of Semi-Circular Micromachined Beams

1999 ◽  
Author(s):  
Chingfu Tsou ◽  
Weileun Fang
Keyword(s):  
Thin Films ◽  
Residual Stress ◽  
Residual Stresses ◽  
Plane Deformation ◽  
The Other ◽  
Side View ◽  
End Conditions ◽  
Out Of Plane ◽  
Circular Beam ◽  
The Mean

Abstract In this research, a semi-circular micromachined beam is proposed to reduce the out-of-plane deformation caused by the residual stresses. The side view of the semi-circular beam is similar to that of the cantilever. However, the end conditions of the semi-circular beam are similar to that of the microbridge. Although the micromachined cantilever would not be deformed by the mean compression, it is bent significantly by the residual gradient stress. On the other hand, the microbridge would not be bent by the gradient residual stress, however, it would be buckled by the mean compression. As demonstrated through the analytical and experimental results, the out-of-plane deformation due to bending and buckling is significantly reduced for the semi-circular micromachined beam. Thus, the flatness of the micromachined suspensions is improved. The more traditional techniques in which the out-of-plane deformation is reduced by lowering the net residual stresses of thin films can be supplemented by the use of semi-circular micromachined beam.

Interface Reaction Enhanced Epitaxial Growth of Barium Ferrite Magnetic Thin Films

1994 ◽  
Vol 357 ◽  
Author(s):  
Jinshan Li ◽  
Robert Sinclair ◽  
Stephen S. Rosenblum ◽  
Hidetaka Hayashi
Keyword(s):  
Thin Films ◽  
Epitaxial Growth ◽  
Transition Layer ◽  
Barium Ferrite ◽  
Lattice Mismatch ◽  
Interface Reaction ◽  
Magnetic Thin Films ◽  
Point Of View ◽  
Si Substrates ◽  
Out Of Plane

AbstractUsing facing target sputtering, crystalline magnetoplumbite-type barium ferrite (BaFe12O19 or BaM) thin films have been prepared in-situ at a substrate temperature of 640°C without postdeposition annealing. BaM thin films grow randomly if they are directly deposited onto Si or thermally oxidized Si substrates. However, deposited onto a sputtered ZnO layer (∼230Å) on Si substrates, BaM thin films show excellent c-axis out-of-plane texture with a 0.2° c-axis dispersion angle, as indicated by X-ray diffraction (XRD) study. Cross section transmission electron microscopy (TEM) reveals that the textured films epitaxially grow on a transition layer, which is formed between BaM and ZnO. No direct epitaxial relation between BaM and ZnO was observed. This transition layer is identified by TEM and XRD as ZnFe2O4, which, from a structure point of view, reduces the lattice mismatch between BaM and ZnO, and also enhances the c-axis out-of-plane epitaxial growth.

RHYNCHOLITES AND THE PROBLEM OF NARROW AND BROAD CONCEPTION OF TAXONS

2018 ◽  
pp. 12-17 ◽  
Author(s):  
I. R. Khuzina ◽  
V. N. Komarov
Keyword(s):  
Sexual Dimorphism ◽  
Morphological Characteristics ◽  
Mass Scale ◽  
Individual Variability ◽  
Point Of View ◽  
The Other ◽  
New Taxon ◽  
Artificial System ◽  
Broad Understanding

The paper considers a point of view, based on the conception of the broad understanding of taxons. According to this point of view, rhyncholites of the subgenus Dentatobeccus and Microbeccus are accepted to be synonymous with the genus Rhynchoteuthis, and subgenus Romanovichella is considered to be synonymous with the genus Palaeoteuthis. The criteria, exercising influence on the different approaches to the classification of rhyncholites, have been analyzed (such as age and individual variability, sexual dimorphism, pathological and teratological features, degree of disintegration of material), underestimation of which can lead to inaccuracy. Divestment of the subgenuses Dentatobeccus, Microbeccus and Romanovichella, possessing very bright morphological characteristics, to have an independent status and denomination to their synonyms, has been noted to be unjustified. An artificial system (any suggested variant) with all its minuses is a single probable system for rhyncholites. The main criteria, minimizing its negative sides and proving the separation of the new taxon, is an available mass-scale material. The narrow understanding of the genus, used in sensible limits, has been underlined to simplify the problem of the passing the view about the genus to the other investigators and recognition of rhyncholites for the practical tasks.

Masonry: the brittle or plastic material?

2019 ◽  
pp. 22-28
Keyword(s):  
Plastic Material ◽  
Experimental Studies ◽  
Point Of View ◽  
Plastic Properties ◽  
Plastic Deformations ◽  
Base Materials ◽  
Stress States ◽  
Creep Deformations ◽  
Structural Point

The results of experimental studies of masonry on the action of dynamic and static (short-term and long-term) loads are presented. The possibility of plastic deformations in the masonry is analyzed for different types of force effects. The falsity of the proposed approach to the estimation of the coefficient of plasticity of masonry, taking into account the ratio of elastic and total deformations of the masonry is noted. The study of the works of Soviet scientists revealed that the masonry under the action of seismic loads refers to brittle materials in the complete absence of plastic properties in it in the process of instantaneous application of forces. For the cases of uniaxial and plane stress states of the masonry, data on the coefficient of plasticity obtained from the experiment are presented. On the basis of experimental studies the influence of the strength of the so-called base materials (brick, mortar) on the bearing capacity of the masonry, regardless of the nature of the application of forces and the type of its stress state, is noted. The analysis of works of prof. S. V. Polyakov makes it possible to draw a conclusion that at the long application of the load, characteristic for the masonry are not plastic deformations, but creep deformations. It is shown that the proposals of some authors on the need to reduce the level of adhesion of the mortar to the brick for the masonry erected in earthquake-prone regions in order to improve its plastic properties are erroneous both from the structural point of view and from the point of view of ensuring the seismic resistance of structures. It is noted that the proposal to assess the plasticity of the masonry of ceramic brick walls and large-format ceramic stone with a voidness of more than 20% is incorrect, and does not meet the work of the masonry of hollow material. On the basis of the analysis of a large number of research works it is concluded about the fragile work of masonry.

Residual stress and mechanical properties of polyimide thin films

2009 ◽  
Vol 113 (2) ◽  
pp. 976-983 ◽  
Author(s):  
Wonbong Jang ◽  
Jongchul Seo ◽  
Choonkeun Lee ◽  
Sang-Hyon Paek ◽  
Haksoo Han
Keyword(s):  
Thin Films ◽  
Mechanical Properties ◽  
Residual Stress

scholarly journals Strong texture tuning along different crystalline directions in glass-supported CeO2 thin films by ultrasonic spray pyrolysis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Inti Zumeta-Dubé ◽  
José Manuel García Rangel ◽  
Jorge Roque ◽  
Issis Claudette Romero-Ibarra ◽  
Mario Fidel García Sánchez
Keyword(s):  
Thin Films ◽  
Spray Pyrolysis ◽  
Spray Pyrolysis Technique ◽  
Morphological Characteristics ◽  
Ultrasonic Spray Pyrolysis ◽  
Cost Effective ◽  
Growth Direction ◽  
Large Area ◽  
Smart Windows ◽  
Ultrasonic Spray

AbstractThe strong facet-dependent performance of glass-supported CeO2 thin films in different applications (catalysis, smart windows, etc.) has been the target of diverse fundamental and technological approaches. However, the design of accurate, cost-effective and scalable methods with the potential for large-area coverage that produce highly textured glass-supported CeO2 thin films remains a technological challenge. In the present work, it is demonstrated that under proper tuning conditions, the ultrasonic spray pyrolysis technique enables one to obtain glass-supported polycrystalline CeO2 films with noticeable texture along both the (100) and (111) directions, as well as with randomly oriented crystallites (no texture). The influence of flow rates, solution molarity, and substrate temperature on the texture and morphological characteristics, as well as optical absorption and Raman response of the deposited films, is evaluated. The obtained results are discussed on the basis of the combined dependence of the CeO2-exposed surfaces on the thermodynamic stability of the corresponding facets and the reaction kinetics, which modulate the crystallite growth direction.

scholarly journals Statistical analysis of the reproducibility of residual stress measurements in cold extruded parts

2021 ◽  
Author(s):  
Fabian Jaeger ◽  
Alessandro Franceschi ◽  
Holger Hoche ◽  
Peter Groche ◽  
Matthias Oechsner
Keyword(s):  
Residual Stress ◽  
Statistical Analysis ◽  
Stress Measurement ◽  
Industrial Applications ◽  
Cold Extrusion ◽  
X Ray Diffraction ◽  
Forming Process ◽  
X Ray ◽  
Stress States ◽  
Key Aspects

AbstractCold extruded components are characterized by residual stresses, which originate from the experienced manufacturing process. For industrial applications, reproducibility and homogeneity of the final components are key aspects for an optimized quality control. Although striving to obtain identical deformation and surface conditions, fluctuation in the manufacturing parameters and contact shear conditions during the forming process may lead to variations of the spatial residual stress distribution in the final product. This could lead to a dependency of the residual stress measurement results on the relative axial and circumferential position on the sample. An attempt to examine this problem is made by the employment of design of experiments (DoE) methods. A statistical analysis of the residual stress results generated through X-Ray diffraction is performed. Additionally, the ability of cold extrusion processes to generate uniform stress states is analyzed on specimens of austenitic stainless steel 1.4404 and possible correlations with the pre-deformed condition are statistically examined. Moreover, the influence of the coating, consisting of oxalate and a MoS2 based lubricant, on the X-Ray diffraction measurements of the surface is investigated.

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