Journal articles on the topic 'Surface substrate'

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1

Kovalev, Alexander E., Alexander E. Filippov, and Stanislav N. Gorb. "Insect wet steps: loss of fluid from insect feet adhering to a substrate." Journal of The Royal Society Interface 10, no. 78 (January 6, 2013): 20120639. http://dx.doi.org/10.1098/rsif.2012.0639.

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Reliable attachment ability of insect adhesive pads is proposed to be due to pad secretion. It has been shown that surface roughness strongly reduces adhesion forces of insect pads. This effect has been explained by decreased contact area and rapid fluid absorption from the pad surface by rough surfaces. However, it remains unclear how the fluid flows on rough substrates having different roughness parameters and surface energy. In this paper, we numerically studied the fluid flow on rough substrates during contact formation. The results demonstrate that an increase in the density of the substrate structures leads to an increase in fluid loss from the pad: substrates with a fine roughness absorb pad fluid faster. Decreased affinity of the solid substrate to the fluid has a more remarkable effect on the fluid loss and leads to a decrease in the fluid loss. With an increase in the aspect ratio of the substrate irregularities (porosity), the fluid loss is decreased. The numerical results obtained agree well with previous observations on insects and experimental results on nanoporous substrata. The significance of the obtained results for understanding biological wet adhesives is discussed.
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2

Chaky, J., K. Anderson, M. Moss, and L. Vaillancourt. "Surface Hydrophobicity and Surface Rigidity Induce Spore Germination in Colletotrichum graminicola." Phytopathology® 91, no. 6 (June 2001): 558–64. http://dx.doi.org/10.1094/phyto.2001.91.6.558.

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We investigated the relationship between physical characteristics of artificial surfaces, spore attachment, and spore germination in Colletotrichum graminicola. Surface hydrophobicity and surface rigidity were both signals for breaking dormancy and initiating spore germination, but spore attachment alone was not an important inducing signal. The presence of a carbon source overrode the necessity for a rigid, hydrophobic substrate for spore germination. Spore attachment was typically stronger to more hydrophobic surfaces, but certain hydrophilic surfaces also proved to be good substrates for spore attachment. In contrast to spore germination, appressorial induction was more dependent on attachment to a rigid substrate than it was on surface hydrophobicity. Appressoria were induced efficiently on hydrophilic surfaces, as long as there was significant conidial attachment to those surfaces.
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3

Xie, Z. Y., C. H. Wei, L. Y. Li, J. H. Edgar, J. Chaudhuri, and C. Ignatiev. "Effects of Surface Preparation on Epitaxial GaN on 6H-SiC Deposited Via MOCVD." MRS Internet Journal of Nitride Semiconductor Research 4, S1 (1999): 281–86. http://dx.doi.org/10.1557/s1092578300002593.

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A comparison was made of 6H-SiC surfaces etched with H2, C2H4/H2, and HCl/H2, and the resulting crystal quality of epitaxial GaN films deposited on these substrates. To remove the many fine scratches and to smooth the rough surfaces typical of commercial SiC substrates, the Si-face 6H-SiC substrates were etched in H2, C2H4/H2, and HCl/H2 at 145 °C. GaN was subsequently deposited on these etched surfaces after first depositing a low temperature GaN buffer layer via metalorganic chemical vapor deposition (MOCVD). The surface morphologies after etching and after GaN deposition were characterized by atomic force microscopy and Normaski differential interference contrast microscopy, while the crystal quality of the GaN films was assessed by double crystal x-ray rocking curves and x-ray topography. 6H-SiC substrate surfaces were improved in terms of the removal of scratches and the reduction of surface roughness, and both surface morphology and crystal quality of the subsequently deposited GaN films were enhanced. However, the dislocation density was not decreased by the surface etching. The best GaN film was produced by etching the substrate in pure H2 for 40 minutes before growth. Recommendations for the optimum substrate treatment are made.
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4

Steigmann, D. J., and R. W. Ogden. "Elastic surface—substrate interactions." Proceedings of the Royal Society of London. Series A: Mathematical, Physical and Engineering Sciences 455, no. 1982 (February 8, 1999): 437–74. http://dx.doi.org/10.1098/rspa.1999.0320.

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5

Lin, I.-Nan. "Surface acoustic wave substrate." Journal of the Acoustical Society of America 126, no. 2 (2009): 931. http://dx.doi.org/10.1121/1.3204337.

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6

Zhang, An Liang, and Yan Zha. "Transportation of Droplets within Two Substrates by Help of Surface Acoustic Wave." Applied Mechanics and Materials 160 (March 2012): 92–96. http://dx.doi.org/10.4028/www.scientific.net/amm.160.92.

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It is usually difficult to integrate all operation units of complicated biochemical analysis systems into a micro-fluidic substrate. A multi substrate micro-fluidic system (MSMS) is a good option, in which operation units can be integrated into two or more substrates. Thus, it is necessary to transport droplets between two substrates. In this paper, a new method for transporting droplets between two substrates has been proposed based on surface acoustic wave (SAW). It is composed of a 128°YX-LiNbO3 piezoelectric substrate (substrate 1) and an arc-shaped polymer. The arc-shaped polymer is seamlessly adhered to the piezoelectric substrate, and the lowest end is above another a substrate (substrate 2) with some distances. After a droplet in the substrate 1 is propelled to the arc-shaped polymer by SAW, it will slide off the polymer due to its gravity, and transported onto the substrate 2. Theoretical formulas of forces acted on the droplet have been deduced and the condition of the droplet sliding off the arc-shaped has also been obtained. Red dye solution droplets were used in the transporting experiments. Results show that the transportation of droplets is decided on curvature radius and hydrophobic property of the arc-shaped polymer and the droplet volumes. As applications, mixture operations have been implemented in substrate 2 after droplets have been transported from the substrate 1.
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7

Слюсарь, Денис Витальевич, Владимир Петрович Колесник, Олег Николаевич Чугай, Леонид Васильевич Литовченко, Николай Петрович Степанушкин, Сергей Леонидович Абашин, and Сергей Владимирович Олейник. "ВЛИЯНИЕ РАЗЛИЧНЫХ ФАКТОРОВ НА МОРФОЛОГИЮ ПОВЕРХНОСТИ ПОКРЫТИЙ ТИПА WC, ОСАЖДЕННЫХ ИОННО-ПЛАЗМЕННЫМ МЕТОДОМ." Aerospace technic and technology, no. 6 (December 20, 2018): 76–82. http://dx.doi.org/10.32620/aktt.2018.6.10.

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It was studied the morphology of the WС coatings’ surfaces formed by the ion-plasma method on the substrates of БрАЖ9-4 tinless bronze and 12Х18Н9Т stainless steel. Initially, the substrate had the same roughness. The coatings were formed by spraying a lot of cathodes-targets made of BA brand tungsten and ОСЧ 7-3 spectral-pure graphite. The coating thickness was 8 ... 9 μm. The scanning electron microscope РЭМ 106 investigated the surface morphology of various areas of both the substrates and formed coatings. It is revealed the features of the morphology of the substrates and WC coatings’ surfaces determined by the composition of the substrate as well as the remoteness of the investigated area from its edge. It is noted that, regardless of the substrate material, the coatings consist of a multitude of grains, the sizes of which vary in the same limits of 0.5 ... 3 μm. However, in the case of a coating formed on a bronze substrate, grains with a size of 2 ... 3 μm quantitatively predominate. At the same time, the coatings formed on the steel substrate, the size of the predominant grains do not exceed 1 μm. At the edge of the bronze substrate, the grain size varies over a wider range of 0.5 ... 5 μm. The size of the predominant grains is 2 ... 5 μm. It was concluded that one of the main factors affecting the morphology of tungsten carbide coatings is the surface roughness of the substrate based on the analysis of the surface morphology of the substrates before and after their ionic cleaning. That roughness of the substrate arose during its ionic cleaning before forming the coating. Attention is drawn to the fact that the difference in the sputtering coefficients of the elements that form the substrate is of particular importance. This difference in coefficients predetermines the peculiarities of the surface morphology of the substrate after cleaning, which is confirmed by the literature data on the sputtering coefficients of the elements (Fe, Cr, Ni, Ti, Cu, Cu, and Fe) that are part of the applied bronze and steel grades. In addition, the concentration of the electric field at the edge of the substrate plays an important role in cleaning the substrate and coating formation
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8

Czarnecki, Sławomir, Jerzy Hoła, and Łukasz Sadowski. "The Use of a 3D Scanner for Evaluating the Morphology of a Sandblasted Concrete Surface." Key Engineering Materials 662 (September 2015): 193–96. http://dx.doi.org/10.4028/www.scientific.net/kem.662.193.

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The possibility of the non-destructive testing of concrete surface morphology by means of a new-generation 3D laser scanner is presented. The test results for a reference concrete substrate surface and a sandblasted concrete substrate surface are reported. The effect of sandblasting on the morphology of the concrete surfaces of the substrates is highlighted. The results are presented as three-dimensional images and the values of the morphology parameters are compared in a table.
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9

Lukauskaitė, Raimonda, Algirdas Vaclovas Valiulis, Olegas Černašėjus, and Jelena Škamat. "RESEARCH INTO NI-CR-SI-B COATING SPRAYED ONTO ALUMINIUM SUBSTRATE USING THE METHOD OF PLASMA SPRAY / NI-CR-SI-B DANGOS, UŽPURKŠTOS ANT ALIUMINIO SUBSTRATO PLAZMINIO PURŠKIMO BŪDU, TYRIMAS." Mokslas - Lietuvos ateitis 6, no. 4 (February 4, 2013): 546–49. http://dx.doi.org/10.3846/mla.2012.89.

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The article deals with Ni base coatings deposited on aluminium substrate applying the method of plasma spray. The purpose of the conducted research is to improve the physical and mechanical properties of coatings on the surface of aluminium alloy work pieces. Spraying on aluminium alloys encounters serious problems, and therefore this work analyses the ways to make the situation more favourable. Before spraying, the surfaces of substrates were modified employing chemical and mechanical pre-treatment methods. The aim of pre-treating aluminium alloys was to remove oxide layers from the aluminium surface. Coating microstructures and porosity were characterised applying optical microscopy. Differences in the roughness of pre-treated surfaces have been determined referring to profilometry. The paper investigates the influence of the adhesion of plasma spray coatings on aluminium surface pretreatment. Microhardness technique was applied for measuring the hardness of coatings. The study also describes and compares the mechanical properties of Ni base coatings deposited on different pre-treated aluminium substrates using plasma spray. Santrauka Straipsnyje nagrinėjamas Ni-Cr-Si-B dangos dengimas ant aliuminio substratų plazminiu purškimo būdu. Tyrimo tikslas – sukurti aliuminio lydinių paviršiuje geresnių fizinių ir mechaninių savybių dangas. Aliuminio lydinių terminį purškimą apsunkina tanki, aukštos lydymosi temperatūros oksido plėvelė substrato paviršiuje. Aliuminio substratų paviršiai prieš purškimą buvo apdorojami cheminiais ir mechaniniais apdorojimo būdais. Pagrindinis aliuminio lydinių apdorojimo tikslas buvo pašalinti oksidų sluoksnį nuo aliuminio paviršiaus ir paveikti substrato paviršiaus šiurkštumą. Aliuminio paviršiaus šiurkštis po apdorojimų buvo tiriamas profilometru. Dangų mikrostruktūra ir porėtumas buvo nagrinėjami optinės mikroskopijos būdu taikant fazių ir morfologijos analizės programą. Buvo nustatyta plazminio purškimo dangų adhezijos reikšmių priklausomybė nuo aliuminio paviršiaus apdorojimo būdų. Eksperimentinių tyrimų metu buvo analizuojama purškimo proceso technologinių parametrų įtaka užpurkštų dangų porėtumui ir kietumui.
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10

Stockdale, Bill. "Substrate Materials Micromachining and Surface Considerations." JALA: Journal of the Association for Laboratory Automation 4, no. 2 (May 1999): 35–39. http://dx.doi.org/10.1177/221106829900400208.

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Subject material presented describes substrate materials and their processing as key elements in microsystems technology manufacturing (MST) for Biochips (DNA arrays), Electronic MEMS (Micro-Electro-Mechanical) Devices and electro-optics. Material choices are primarily glass, quartz and silicon, each of which may require mechanical features and exact surface finishes to enable design function and manufacturing. This paper will address some basic approaches to determining what substrates require for specific designs and manufacturing processes.
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11

Syafiq, A., B. Vengadaesvaran, A. K. Pandey, and Nasrudin Abd Rahim. "Superhydrophilic Smart Coating for Self-Cleaning Application on Glass Substrate." Journal of Nanomaterials 2018 (December 3, 2018): 1–10. http://dx.doi.org/10.1155/2018/6412601.

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In general, superhydrophilic coating on glass substrate possesses water contact angle (WCA) below 10° and contains high self-cleaning properties in outdoor environment as compared to noncoated glass substrate panels. In this study, the superhydrophilic coating behavior on glass substrate has been developed. The micro- and nanosized titanium dioxide (TiO2) particles have been utilized to improve the surface roughness, and the polypropylene glycol (PPG) has been utilized to increase the surface energy of glass substrates. The wettability of coating surface shows the coating possess water contact angle (WCA) as low as 5° and suddenly reduce to 0° after 10 s. Superhydrophilic coated glass clearly shows excellent dirt repellent against dilute ketchup solution due to the absence of dirt streak on the glass surface. Meanwhile, the dirt streak is present on the bare glass surface indicating its weak self-cleaning property. The developed superhydrophilic coating on glass substrate was also found to have great antifog property compared to the bare glass substrate. Superhydrophilic surfaces have showed free tiny droplet even at 130°C of hot boiling bath for 10 min and completely dry after 1 min. The superhydrophilic coating surfaces have demonstrated free water streak after impacting with harsh water spraying for 5 min confirming that the superhydrophilic coating on glass substrate is antiwater streak.
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12

Aleksandrovych, M., G. Castanet, S. Burian, F. Lemoine, D. Lacroix, and M. Isaiev. "Effect of Surface Nano-Texturing on Wetting Properties: Molecular Dynamics Study." Ukrainian Journal of Physics 65, no. 9 (August 26, 2020): 817. http://dx.doi.org/10.15407/ujpe65.9.817.

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Molecular dynamics simulations describing the equilibrium shape of a nanodroplet located on the solid substrate are presented for the cases of a “cylindrical water droplet” on silicon substrates. Several examples of the structuration of the solid substrate surface are simulated, i.e.: atomistic flat substrate and substrates with ordered nanopillars and nanopores. The adhesives forces between molecules of the substrate and the fluid are modified to change the wettability. Three wetting configurations are considered in this work for the smooth surface: (i) hydrophilic (0 = 30∘), (ii) hydrophobic (0 = 136∘), and (iii) an intermediate regime (0 = 80∘). Further, the dependence of the wetting angle as a function of the surface state is studied in details for the above-mentioned configurations.
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13

ul Hassan, Jawad, Axel Meyer, Semih Cakmakyapan, Ozgur Kazar, Jan Ingo Flege, Jens Falta, Ekmel Ozbay, and Erik Janzén. "Surface Evolution of 4H-SiC(0001) during In Situ Surface Preparation and its Influence on Graphene Properties." Materials Science Forum 740-742 (January 2013): 157–60. http://dx.doi.org/10.4028/www.scientific.net/msf.740-742.157.

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The evolution of SiC surface morphology during graphene growth process has been studied through the comparison of substrate surface step structure after in-situ etching and graphene growth in vacuum. Influence of in-situ substrate surface preparation on the properties of graphene was studied through the comparison of graphene layers on etched and un-etched substrates grown under same conditions.
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14

Lin, Bo, Chen Zheng, Qingying Zhu, and Fang Xie. "Surface-induced phase transitions in thin films of dendrimer block copolymers." e-Polymers 20, no. 1 (March 2, 2020): 76–84. http://dx.doi.org/10.1515/epoly-2020-0009.

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AbstractThe phase morphologies and phase transitions of dendrimer block copolymer thin films confined between two homogeneous, planar hard substrates had been investigated by a three-dimensional real space self-consistent field theory (SCFT). From the perspectives of property and strength of the preferential substrate, when the film system confined within neutral substrates, the thinner film was easier to take the undulated and perpendicular cylinder phases. For the attractive preference of the substrate on block segment A, the polymer films tended to take the surface-wetting structures that was composed by block segment A. On the contrary, for the repulsive preference of the substrate on block segment A, a phase transition of cylinder-lamellae could be observed increasing with the relative surface strength of the preferential substrate.
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15

Žigon, Jure, Mirko Kariž, and Matjaž Pavlič. "Surface Finishing of 3D-Printed Polymers with Selected Coatings." Polymers 12, no. 12 (November 26, 2020): 2797. http://dx.doi.org/10.3390/polym12122797.

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Surface treatment of 3D-printed objects with coatings, besides protection against environmental influences, offers the improvement of visual appearance of the printed elements. In order to design an optimum surface system, the physical and chemical properties of polymers surfaces should be well-known. In the present study, 3D-printed samples of acrylonitrile-butadiene-styrene, poly(lactic acid) and poly(lactic acid) with wood flour additive were coated with three different types of coating, namely solvent borne alkyd coating, water borne acrylic coating and coating made of acrylonitrile-butadiene-styrene diluted in acetone. The surface properties of substrates and the properties of surface systems were assessed with different methods. The results revealed the surfaces of polymers having hydrophobic character, whereas the color, gloss, surface roughness and coating film thickness of coated surfaces depend on the characteristics of particular coatings. Finally, the adhesion of coatings was shown to be appropriate, but dependent on substrate surface porosity and chemical properties of both substrate surface and coating asset.
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16

Pawlak, Jakub, Antoni Żywczak, Jarosław Kanak, and Marek Przybylski. "Surface-Step-Induced Magnetic Anisotropy in Epitaxial LSMO Deposited on Engineered STO Surfaces." Materials 13, no. 18 (September 17, 2020): 4148. http://dx.doi.org/10.3390/ma13184148.

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Changes in stoichiometry, temperature, strain and other parameters dramatically alter properties of LSMO perovskite. Thus, the sensitivity of LSMO may enable control of the magnetic properties of the film. This work demonstrates the capabilities of interface engineering to achieve the desired effects. Three methods of preparing STO substrates were conducted, i.e., using acid, buffer solution, and deionized water. The occurrence of terraces and their morphology depend on the preparation treatment. Terraces propagate on deposited layers and influence LSMO properties. The measurements show that anisotropy depends on the roughness of the substrate, the method of preparing the substrate, and oxygen treatment. The collected results suggest that the dipolar mechanism may be the source of LSMO anisotropy.
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17

Hosoda, Naoe, and Stanislav N. Gorb. "Underwater locomotion in a terrestrial beetle: combination of surface de-wetting and capillary forces." Proceedings of the Royal Society B: Biological Sciences 279, no. 1745 (August 8, 2012): 4236–42. http://dx.doi.org/10.1098/rspb.2012.1297.

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For the first time, we report the remarkable ability of the terrestrial leaf beetle Gastrophysa viridula to walk on solid substrates under water. These beetles have adhesive setae on their feet that produce a secretory fluid having a crucial role in adhesion on land. In air, adhesion is produced by capillary forces between the fluid-covered setae and the substrate. In general, capillary forces do not contribute to adhesion under water. However, our observations showed that these beetles may use air bubbles trapped between their adhesive setae to walk on flooded, inclined substrata or even under water. Beetle adhesion to hydrophilic surfaces under water was lower than that in air, whereas adhesion to hydrophobic surfaces under water was comparable to that in air. Oil-covered hairy pads had a pinning effect, retaining the air bubbles on their feet. Bubbles in contact with the hydrophobic substrate de-wetted the substrate and produced capillary adhesion. Additional capillary forces are generated by the pad's liquid bridges between the foot and the substrate. Inspired by this idea, we designed an artificial silicone polymer structure with underwater adhesive properties.
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18

HOU, QINGRUN, and J. GAO. "INFLUENCE OF SUBSTRATE TREATMENTS ON MORPHOLOGY AND ADHESION OF CARBON COATINGS ON QUARTZ." Modern Physics Letters B 10, no. 30 (December 30, 1996): 1501–5. http://dx.doi.org/10.1142/s021798499600170x.

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The influence of different treatments of quartz substrate on morphology and adhesion of carbon coatings was studied. The surfaces of quartz substrates were abraded by using fine and coarse abrasive papers respectively to develop rough surface features. Adherent carbon coatings with different surface roughness were obtained. In order to grow adherent carbon coatings with very smooth surfaces, a silicon intermediate layer was grown by means of electron beam evaporation. Carbon coatings deposited on the intermediate layers were adherent to the quartz substrates.
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19

Xu, Fugang, Mengren Xuan, Zixiang Ben, Wenjuan Shang, and Guangran Ma. "Surface enhanced Raman scattering analysis with filter-based enhancement substrates: A mini review." Reviews in Analytical Chemistry 40, no. 1 (January 1, 2021): 75–92. http://dx.doi.org/10.1515/revac-2021-0126.

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Abstract Surface enhanced Raman is a powerful analytical tool with high sensitivity and unique specificity and promising applications in various branches of analytical chemistry. Despite the fabrication of ingenious enhancement substrate used in laboratory research, the development of simple, flexible, and cost-effective substrate is also great important for promoting the application of SERS in practical analysis. Recently, paper and filter membrane as support to fabricate flexible SERS substrates received considerable attentions. Paper-based SERS substrate has been reviewed but no summary on filter-based SERS substrate is available. Compared with paper, filter membrane has unique advantage in robust mechanics, diverse component, and tunable pore size. These characteristics endow the filter-based substrates great advantages for practical SERS analysis including simple and low-cost substrate preparation, high efficiency in preconcentration, separation and detection procedure. Therefore, filter-based substrates have shown great promise in SERS analysis in environment monitoring, food safety with high sensitivity and efficiency. As more and more work has been emerged, it is necessary to summarize the state of such a research topic. Here, the research on filter involved SERS analysis in the past eight years is summarized. A short introduction was presented to understand the background, and then the brief history of filter-based substrate is introduced. After that, the preparation of filter-based substrate and the role of filter are summarized. Then, the application of filter involved SERS substrate in analysis is presented. Finally, the challenges and perspective on this topic is discussed.
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20

Okano, Koji, Kenkichi Kitahara, and Eiji Ushizawa. "Surface Disclinations on Modified Substrate." Japanese Journal of Applied Physics 33, Part 1, No. 11 (November 15, 1994): 6262–67. http://dx.doi.org/10.1143/jjap.33.6262.

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21

Liu, Juhua. "Substrate Integrated Surface-Wave Antenna." IEEE Transactions on Antennas and Propagation 67, no. 8 (August 2019): 5221–30. http://dx.doi.org/10.1109/tap.2019.2916574.

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22

Jones, S. H., L. K. Seidel, K. M. Lau, and M. Harold. "Patterned substrate epitaxy surface shapes." Journal of Crystal Growth 108, no. 1-2 (January 1991): 73–88. http://dx.doi.org/10.1016/0022-0248(91)90355-9.

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23

Koguchi, Hideo. "Adhesion Analysis Considering Surface Energy and Surface Stresses." Key Engineering Materials 297-300 (November 2005): 1736–41. http://dx.doi.org/10.4028/www.scientific.net/kem.297-300.1736.

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A new formulation for an adhesive force between a substrate and an indenter is presented. The boundary condition taking into account surface stresses is used for the present analysis. The surface stress is originated from surface energy. A paraboloidal indenter is pressed to the substrate, and then adhesion occurs between both surfaces. Surface energy and surface stress will vary at the adhesion surface, and then the surfaces deform in a concave way. An attractive force occurs to keep the contact of two adhesion surfaces. In the present paper, an effect of surface stress on the adhesive force will be clarified.
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24

Akbari, Mahmood, Mohammed Kamruddin, Razieh Morad, and Malik Maaza. "Electrical Tunability of Surface Tension of Vertical Graphene Nanosheets." MRS Advances 5, no. 44 (2020): 2291–98. http://dx.doi.org/10.1557/adv.2020.209.

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ABSTRACTThe contact angle is a material property determined by the surface tensions between substrate, liquid and the air. In this study, the surface wettability of vertical graphene nanosheets (VGNs) which are carbon nanostructures consisting of a few layers of graphene sheets vertically standing on the substrates, were developed by applying different voltages on the substrate. The contact angle of the water droplet on VGNs/Cu decreased from 123° to 16° with increasing the applied voltage which indicated the hydrophobic and hydrophilic transition of VGNs surfaces. It is anticipated that this member of the carbon material family (VGNs) could serve as a tunable wettability coting for future improvements in electronic devices and open a new perspective to the construction of smart material surfaces.
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25

Savin, Alexander V., and Yuriy A. Kosevich. "Modeling of One-Side Surface Modifications of Graphene." Materials 12, no. 24 (December 12, 2019): 4179. http://dx.doi.org/10.3390/ma12244179.

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We model, with the use of the force field method, the dependence of mechanical conformations of graphene sheets, located on flat substrates, on the density of unilateral (one-side) attachment of hydrogen, fluorine or chlorine atoms to them. It is shown that a chemically-modified graphene sheet can take four main forms on a flat substrate: the form of a flat sheet located parallel to the surface of the substrate, the form of convex sheet partially detached from the substrate with bent edges adjacent to the substrate, and the form of a single and double roll on the substrate. On the surface of crystalline graphite, the flat form of the sheet is lowest in energy for hydrogenation density p < 0.21 , fluorination density p < 0.20 , and chlorination density p < 0.16 . For higher attachment densities, the flat form of the graphene sheet becomes unstable. The surface of crystalline nickel has higher adsorption energy for graphene monolayer and the flat form of a chemically modified sheet on such a substrate is lowest in energy for hydrogenation density p < 0.47 , fluorination density p < 0.30 and chlorination density p < 0.21 .
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26

Zhu, Cong Rong, Qin Xu, Ju Long Yuan, Dong Hui Wen, and Bing Hai Lv. "Experimental Study on the Ultraprecision Lapping Technology of the Copper Substrates for Alloy Films." Key Engineering Materials 359-360 (November 2007): 349–54. http://dx.doi.org/10.4028/www.scientific.net/kem.359-360.349.

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To obtain the amorphous alloy films with superior properties by method of electrochemical deposition, the accuracy requirement for the copper substrates for Alloy Films is extraordinarily strict. The ultraprecision lapping technology for the copper substrate employing polyurethane polishing pad and flannel pad is studied in this paper, surface roughness, material removal rate and change process of surface construction of copper substrates are discussed. The influences of the different lapping parameters on the surface roughness, material removal rate and the influences of lapping load on copper substrate surface formation in the ultraprecision lapping process of copper substrate are both discussed. Experiment results show that the surface scratch will disappear by employing polyurethane polishing pad and flannel pad, and an extremely smooth surface of copper substrate with roughness 6nm Ra is obtained in the final finishing lapping process.
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27

Linehan, D. S., E. P. Kvam, L. Hou, and M. W. McElfresh. "Control of epitaxial growth orientation in YBa2Cu3O7−δ films on vicinal (110) SrTiO3 substrates." Journal of Materials Research 13, no. 10 (October 1998): 2791–99. http://dx.doi.org/10.1557/jmr.1998.0383.

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Films of Yba2Cu3O7−δ (YBCO) were grown on (001), exact and vicinal (110), and (111) SrTiO3 single crystal substrates by pulsed laser deposition, and evaluated by x-ray diffraction and scanning force microscopy (AFM). It was observed that the YBCO was always epitaxially aligned to the substrate with the [001] (c-axis) parallel to a substrate cube axis direction. For the exact (001), (110), and (111) surfaces, there were one, two, and three orientations, respectively. For the vicinal (110) surfaces, however, there was usually only one discernible c-axis orientation, corresponding to a single {013} film surface orientation. The reduction of the (110) surface twofold symmetry by use of a vicinal substrate thus allowed controlled growth of a YBCO single crystal with an inclined c-axis orientation.
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28

Ferraris, Sara, Sergio Perero, and Graziano Ubertalli. "Surface Activation and Characterization of Aluminum Alloys for Brazing Optimization." Coatings 9, no. 7 (July 23, 2019): 459. http://dx.doi.org/10.3390/coatings9070459.

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Brazing of Al-alloys is of interest in many application fields (e.g., mechanical and automotive). The surface preparation of substrates and the in depth investigation of the interface reaction between aluminum substrates and brazing materials is fundamental for a proper understanding of the process and for its optimization. The interaction between two aluminum based substrates (Al5182 and Al6016) and two studied brazing materials (pure Zn and for the first time ZAMA alloy) has been studied in simulated brazing condition in order to define the best surface preparation conditions and combination substrate-brazing material to be used in real joining experiments. Three different surface preparations were considered: polishing and cleaning, application of flux and vacuum plasma etching (Ar) followed by sputtering coating with Zn. Macroscopic observation of the samples surface after “brazing”, optical microscopy, and microhardness measurements on the cross-section and XRD measurements on the top surface gave a comprehensive description of the phenomena occurring at the interface between the substrate and the brazing alloy which are of interest to understand the brazing process and for the detection of the best conditions to be used in brazing. Plasma etching (Ar) followed by sputtering coating with Zn resulted a promising solution in case of Al5182 brazed with Zn, while the addition of flux was more effective in case of Al6016 substrate. ZAMA alloy demonstrated good interface reactivity with both Al6016 and Al5182 alloys, particularly on only cleaned surfaces.
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29

Xing, Juan, Xianchao Pan, Jinfeng Wang, and Yanfeng Luo. "Substrate chemistry regulates the surface phase separation of polyurethane films." Functional Materials Letters 10, no. 05 (October 2017): 1750063. http://dx.doi.org/10.1142/s1793604717500631.

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The effect of substrate chemistry on surface phase separation of polyurethane films were investigated by using self-assembled monolayer (SAM) with chemically different modifications, i.e. hydroxy (–OH) and methyl (–CH3) end groups. Results showed that hydrophilic (–OH) and hydrophobic end groups (–CH[Formula: see text] could respectively promote the aggregation of hard and soft segments at polyurethane–substrate interface, which further regulates the phase separation of polyurethane surface that contacts the substrate. The aggregation of hard segments tended to enhance the surface smoothness of polyurethane films, especially on hydrophilic substrates with hydroxy modification. Further analysis of tensile testing revealed that the regulation of surface phase separation had no effect on the shape memory effect of polyurethane films. These findings suggest that the chemical properties of the substrates could regulate the phase separation and may provide some guidance on the design of specific polyurethane with desired morphology and properties.
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30

Graeber, Gustav, Thomas M. Schutzius, Hadi Eghlidi, and Dimos Poulikakos. "Spontaneous self-dislodging of freezing water droplets and the role of wettability." Proceedings of the National Academy of Sciences 114, no. 42 (September 25, 2017): 11040–45. http://dx.doi.org/10.1073/pnas.1705952114.

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Spontaneous removal of liquid, solidifying liquid and solid forms of matter from surfaces, is of significant importance in nature and technology, where it finds applications ranging from self-cleaning to icephobicity and to condensation systems. However, it is a great challenge to understand fundamentally the complex interaction of rapidly solidifying, typically supercooled, droplets with surfaces, and to harvest benefit from it for the design of intrinsically icephobic materials. Here we report and explain an ice removal mechanism that manifests itself simultaneously with freezing, driving gradual self-dislodging of droplets cooled via evaporation and sublimation (low environmental pressure) or convection (atmospheric pressure) from substrates. The key to successful self-dislodging is that the freezing at the droplet free surface and the droplet contact area with the substrate do not occur simultaneously: The frozen phase boundary moves inward from the droplet free surface toward the droplet–substrate interface, which remains liquid throughout most of the process and freezes last. We observe experimentally, and validate theoretically, that the inward motion of the phase boundary near the substrate drives a gradual reduction in droplet–substrate contact. Concurrently, the droplet lifts from the substrate due to its incompressibility, density differences, and the asymmetric freezing dynamics with inward solidification causing not fully frozen mass to be displaced toward the unsolidified droplet–substrate interface. Depending on surface topography and wetting conditions, we find that this can lead to full dislodging of the ice droplet from a variety of engineered substrates, rendering the latter ice-free.
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31

Stark, Alyssa Y., and Stephen P. Yanoviak. "Adhesion and Running Speed of a Tropical Arboreal Ant (Cephalotes atratus) on Rough, Narrow, and Inclined Substrates." Integrative and Comparative Biology 60, no. 4 (June 13, 2020): 829–39. http://dx.doi.org/10.1093/icb/icaa078.

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Synopsis Arboreal ants must navigate variably sized and inclined linear structures across a range of substrate roughness when foraging tens of meters above the ground. To achieve this, arboreal ants use specialized adhesive pads and claws to maintain effective attachment to canopy substrates. Here, we explored the effect of substrate structure, including small and large-scale substrate roughness, substrate diameter, and substrate orientation (inclination), on adhesion and running speed of workers of one common, intermediately-sized, arboreal ant species. Normal (orthogonal) and shear (parallel) adhesive performance varied on sandpaper and natural leaf substrates, particularly at small size scales, but running speed on these substrates remained relatively constant. Running speed also varied minimally when running up and down inclined substrates, except when the substrate was positioned completely vertical. On vertical surfaces, ants ran significantly faster down than up. Ant running speed was slower on relatively narrow substrates. The results of this study show that variation in the physical properties of tree surfaces differentially affects arboreal ant adhesive and locomotor performance. Specifically, locomotor performance was much more robust to surface roughness than was adhesive performance. The results provide a basis for understanding how performance correlates of functional morphology contribute to determining local ant distributions and foraging decisions in the tropical rainforest canopy.
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32

Augulis, R., R. Valiokas, B. Liedberg, and R. Rotomskis. "Atomic Force Microscopy of Self-Assembled Nanostructures of TPPS4 on SAM Substrates." Solid State Phenomena 97-98 (April 2004): 195–200. http://dx.doi.org/10.4028/www.scientific.net/ssp.97-98.195.

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The adsorption of organic molecules on solid surfaces is one of the fundamental processes for the development of molecular-based nanodevices. Here we focus on the adsorption and ordering of the TPPS4-based J-aggregates on silicon and gold as well as on self-assembled monolayer (SAM) surfaces. The SAMs used for the experiments were based on the chemisorption of thiol containing compounds onto gold. Long ω-substituted alkanethiols are spontaneously assembled on gold to form highly ordered and densely packed layers with controllable chemical and physical properties. TPPS4 J-aggregates were dispersed on SAM surfaces, and on plain gold and silicon substrates for comparison. The dimensions of aggregates, measured by means of atomic force microscopy, varied depending on the type of substrate. Long stripe-like aggregates were flattened on the substrate surface, and the height and width of aggregates highly correlated with the polarity of surface groups. For example, the J-aggregates were narrower on hydrophobic substrates (with non-polar groups) and wider on hydrophilic substrates (with polar groups). These observations support the hypothesis, that TPPS4 forms .soft. cylindrical aggregates, that appear flattened on the substrate.
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33

Okamoto, Takeshi, Yasuhisa Sano, Kazuma Tachibana, Kenta Arima, Azusa N. Hattori, Keita Yagi, Junji Murata, Shun Sadakuni, and Kazuto Yamauchi. "Abrasive-Free Planarization of 3-Inch 4H-SiC Substrate Using Catalyst-Referred Etching." Materials Science Forum 679-680 (March 2011): 493–95. http://dx.doi.org/10.4028/www.scientific.net/msf.679-680.493.

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Catalyst-referred etching (CARE) is an abrasive-free planarization method. We used 3-inch and 2-inch 4H-SiC (0001) 4° off-axis substrates to investigate the processing characteristics that are affected by the substrate diameter. The surface roughness of the 3-inch substrate was extremely smooth over the whole substrate. The surface roughness and removal rate of the 3-inch substrate were approximately the same as those of the 2-inch substrate.
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34

Satyanarayan and K. N. Prabhu. "Solder Joint Reliability of Sn-Cu and Sn-Ag-Cu Lead-Free Solder Alloys Solidified on Copper Substrates with Different Surface Roughnesses." Materials Science Forum 830-831 (September 2015): 265–69. http://dx.doi.org/10.4028/www.scientific.net/msf.830-831.265.

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In the present work, the bond strength of Sn-0.7Cu, Sn-0.3Ag-0.7Cu, Sn-2.5Ag-0.5Cu and Sn-3Ag-0.5Cu lead free solders solidified on Cu substrates was experimentally determined. The bond shear test was used to assess the integrity of Sn–Cu and Sn–Ag–Cu lead-free solder alloy drops solidified on smooth and rough Cu substrate surfaces. The increase in the surface roughness of Cu substrates improved the wettability of solders. The wettability was not affected by the Ag content of solders. Solder bonds on smooth surfaces yielded higher shear strength compared to rough surfaces. Fractured surfaces revealed the occurrence of ductile mode of failure on smooth Cu surfaces and a transition ridge on rough Cu surfaces. Though rough Cu substrate improved the wettability of solder alloys, solder bonds were sheared at a lower force leading to decreased shear energy density compared to the smooth Cu surface. A smooth surface finish and the presence of minor amounts of Ag in the alloy improved the integrity of the solder joint. Smoother surface is preferable as it favors failure in the solder matrix.
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35

Mandrile, Luisa, Andrea Giovannozzi, Alessio Sacco, Gianmario Martra, and Andrea Rossi. "Flexible and Transparent Substrates Based on Gold Nanoparticles and TiO2 for in Situ Bioanalysis by Surface-Enhanced Raman Spectroscopy." Biosensors 9, no. 4 (December 17, 2019): 145. http://dx.doi.org/10.3390/bios9040145.

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Flexible and transparent substrates are emerging as low cost and easy-to-operate support for surface-enhanced Raman spectroscopy (SERS). In particular, in situ SERS detection approach for surface characterization in transmission modality can be efficiently employed for non-invasive analysis of non-planar surfaces. Here we propose a new methodology to fabricate a homogenous, transparent, and flexible SERS membrane by the assistance of a thin TiO2 porous layer deposited on the PDMS surface, which supports the uniform loading of gold nanoparticles over large area. The substrate was first characterized for homogeneity, sensitivity and repeatability using a model molecule for SERS, i.e., 7-mercapto-4-methylcoumarin. Satisfactory intra-substrate uniformity and inter-substrates repeatability was achieved, showing an RSD of 10%, and an analytical sensitivity down to 10 nM was determined with an EF of 3.4 × 105 ± 0.4 × 105. Furthermore, SERS detection of pyrimethanil (PMT), a commonly employed pesticide in crops for human consumption, was performed in situ, exploiting the optical transparency of the device, using both model surfaces and non-flat bio-samples. PMT contamination at the phytochemical concentration levels corresponding to commonly used infield doses was successfully detected on the surface of the yellow Ficus benjiamina leaves, supporting the use of this substrate for food safety in-field application.
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36

Changwu Lü, Changwu Lü, Jiajia Wang Jiajia Wang, Xiaoyi Lü Xiaoyi Lü, and Zhenghong Jia Zhenghong Jia. "Silver particles deposited on porous silicon as surface-enhanced Raman scattering active substrate." Chinese Optics Letters 12, s1 (2014): S12401–312404. http://dx.doi.org/10.3788/col201412.s12401.

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37

Satyanarayan and K. N. Prabhu. "Wetting Characteristics of Sn-0.7Cu Lead-Free Solder Alloy on Copper Substrates." Materials Science Forum 710 (January 2012): 569–74. http://dx.doi.org/10.4028/www.scientific.net/msf.710.569.

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In the present work, the effect of surface texture on wetting characteristics of lead-free solder Sn-0.7Cu on copper substrates have been investigated at 298°C. The wetting tests were carried out using FTA 200 (First Ten Angstrom) dynamic contact angle analyzer. The surface texture of copper substrate significantly affected the wetting properties of Sn-0.7Cu solder alloy. Contact angles of about 30° were obtained on Cu substrate having smooth surface texture (Ra = 0.0155µm). On other hand contact angles on rough copper surface texture (Ra = 1.1194µm) were reduced to 20°. The contact angles decreased with increasing surface texture of Cu substrate. For rough Cu substrate, it seems that the solder atoms dissolve into the substrate in the time period of 200-600s.
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38

Deng, Chuyun, Wanyun Ma, and Jia-Lin Sun. "Fabrication of Highly Rough Ag Nanobud Substrates and Surface-Enhanced Raman Scattering ofλ-DNA Molecules." Journal of Nanomaterials 2012 (2012): 1–5. http://dx.doi.org/10.1155/2012/820739.

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Raman scattering signals can be enhanced by several orders of magnitude on surface-enhanced Raman scattering (SERS) substrates made from noble metal nanostructures. Some SERS substrates are even able to detect single-molecule Raman signals. A novel silver nanobud (AgNB) substrate with superior SERS activity was fabricated with a solid-state ionics method. The AgNB substrate was formed by tightly collocated unidirectional 100 nm size silver buds, presenting a highly rough surface topography. Distinct SERS signals of singleλ-DNA molecules in water were detected on AgNB substrates. AgNB substrates were compared with disordered silver nanowire (AgNW) substrates manufactured by the same method through the SERS detection ofλ-DNA solutions. This original AgNB substrate provides a reliable approach towards trace analysis of biomacromolecules and promotes the utilization of the SERS technique in biomedical research.
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39

Januś, M., K. Kyzioł, S. Kluska, J. Konefał-Góral, A. Małek, and S. Jonas. "Plasma Assisted Chemical Vapour Deposition – Technological Design Of Functional Coatings." Archives of Metallurgy and Materials 60, no. 2 (June 1, 2015): 909–14. http://dx.doi.org/10.1515/amm-2015-0228.

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Abstract Plasma Assisted Chemical Vapour Deposition (PA CVD) method allows to deposit of homogeneous, well-adhesive coatings at lower temperature on different substrates. Plasmochemical treatment significantly impacts on physicochemical parameters of modified surfaces. In this study we present the overview of the possibilities of plasma processes for the deposition of diamond-like carbon coatings doped Si and/or N atoms on the Ti Grade2, aluminum-zinc alloy and polyetherketone substrate. Depending on the type of modified substrate had improved the corrosion properties including biocompatibility of titanium surface, increase of surface hardness with deposition of good adhesion and fine-grained coatings (in the case of Al-Zn alloy) and improving of the wear resistance (in the case of PEEK substrate).
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40

Börner, Richard, Michael Penzel, Thomas Junge, and Andreas Schubert. "Design of Deterministic Microstructures as Substrate Pre-Treatment for CVD Diamond Coating." Surfaces 2, no. 3 (September 17, 2019): 497–519. http://dx.doi.org/10.3390/surfaces2030037.

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The coating of highly stressed components with chemical vapor deposition (CVD) diamond can extend their lifetime. In particular, the combination of steel substrates with diamond layers would find many applications in industrial production. However, there are some challenges, for example, the high mismatch in the thermal expansion between steel and diamond, which commonly leads to the delamination of the coating. Thus, a pre-treatment of the substrate surface is needed. Particle blasting has been established in some studies as a suitable process. However, apart from particle residues in the surface of the substrate, these surfaces have a stochastic character, which limits their reproducibility and modification options. This paper presents some instructions for the recording and derivation of defined properties of those surfaces. The conversion of characteristic surface features into quantitative process parameters could serve as the foundation for the manufacturing of deterministic microstructures, especially those produced by ultrasonic vibration superimposed machining. This should increase the reproducibility and the possibilities of the modification with regard to the structural shaping of the functional surface. The design was developed using both a kinematic surface simulation tool as well as a finite elements analysis for the cooling process of the coating–substrate–composite. A high accordance with real finished surfaces was achieved.
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41

Panitchakan, H., and Pichet Limsuwan. "The Properties of Al2O3 Films Deposited onto Al2O3-TiC and Si Substrates by RF Diode Sputtering." Applied Mechanics and Materials 313-314 (March 2013): 126–30. http://dx.doi.org/10.4028/www.scientific.net/amm.313-314.126.

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The Al2O3 films were deposited onto Al2O3-TiC and Si (100) substrates by RF sputtering technique by varying powers sputter target, substrate bias voltages and fixed process pressure 25 mTorr which aim to achieve high deposition rate and investigated film properties onto different types. Result showed significant power sputter target to deposition rate both substrates and film properties depend on type of substrate. The power sputter target at 8kW and substrate bias voltage at -150 V is optimum deposition condition to provide deposition rate is 53.97nm/min for Al2O3-TiC substrate and 51.50nm/min for Si substrate. The Al2O3 film deposited onto Al2O3-TiC substrate surface morphology displayed rather roughness than Al2O3 film deposited onto Si substrate which verified from SEM and AFM as 0.99 nm (Ra) versus 0.46 nm (Ra). The film stress, hardness, reduces modulus and breakdown voltage (BDV) of Al2O3 film deposited were higher than Al2O3 film deposited on Al2O3-TiC substrates which were correspond to surface morphology.
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42

TAKAHASHI, N., T. ZHANG, M. SPANGENBERG, D. GREIG, T. H. SHEN, S. CORNELIUS, E. A. SEDDON, and J. A. D. MATTHEW. "SPIN-RESOLVED PHOTOELECTRON SPECTROSCOPY OF ULTRATHIN Fe FILMS ON GaAs(001)." Surface Review and Letters 09, no. 02 (April 2002): 693–98. http://dx.doi.org/10.1142/s0218625x02002816.

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Thin epitaxial Fe films were grown on singular and vicinal GaAs(001) substrates, and their magnetic and electronic structures were investigated by synchrotron-based spin-resolved and spin-integrated photoelectron spectroscopy with different Fe thickness. There were two types of substrates: one was a Si-doped n-type GaAs(001) surface with doping concentration of 2 × 1018 cm -3 (singular substrate), and the other was orientated by 3° toward the (111)A direction (vicinal substrate). Spin polarization of the secondary electron peak at different growth stages of Fe coverage for the singular substrate sample and the vicinal one were measured. In the case of singular substrates, there was a dependence of their initial surface reconstruction, which is associated with complex domain structure, while no such the dependence was observed in the case of vicinal substrates. The result from the vicinal sample suggests the geometrical influence of the initial surface stoichiometry of the substrate.
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43

Joseph, Benny, and C. S. Menon. "Studies on the Optical Properties and Surface Morphology of Cobalt Phthalocyanine Thin Films." E-Journal of Chemistry 5, no. 1 (2008): 86–92. http://dx.doi.org/10.1155/2008/102948.

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Thin films of Cobalt Phthalocyanine (CoPc) are fabricated at a base pressure of 10-5m.bar using Hind-Hivac thermal evaporation plant. The films are deposited on to glass substrates at various temperatures 318, 363, 408 and 458K. The optical absorption spectra of these thin films are measured. The present studies reveal that the optical band gap energies of CoPc thin films are almost same on substrate temperature variation. The structure and surface morphology of the films deposited on glass substrates of temperatures 303, 363 and 458K are studied using X-ray diffractograms and Scanning Electron Micrographs (SEM), which show that there is a change in the crystallinity and surface morphology due to change in the substrate temperatures. Full width at half maximum (FWHM) intensity of the diffraction peaks is also found reduced with increasing substrate temperatures. Scanning electron micrographs show that these crystals are needle like, which are interconnected at high substrate temperatures. The optical band gap energy is almost same on substrate temperature variation. Trap energy levels are also observed for these films.
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44

Kojima, Kazutoshi, Keiko Masumoto, Sachiko Ito, Akiyo Nagata, and Hajime Okumura. "Development of Homoepitaxial Growth Technique on 4H-SiC Vicinal Off Angled Substrate." Materials Science Forum 778-780 (February 2014): 125–30. http://dx.doi.org/10.4028/www.scientific.net/msf.778-780.125.

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We have investigated key factors for controlling the polytype and surface morphology of 4H-SiC homoepitaxial growth on less than 4ooff-axis substrates. In addition, we characterized the crystal quality and surface quality of the epitaxial layer of an entire 3-inch vicinal off angled substrate. The results suggested that the control of surface free energy, control of the vicinal off angle itself, and high temperature growth, is highly important in controlling the surface morphology and polytype stability of the epitaxial layer grown on a vicinal off angled substrate. We also obtained a high-quality epitaxial layer grown on a 3-inch vicinal off angle substrate, which was comparable to those on 4ooff-axis substrates.
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45

Priestley, Rodney D., Manish K. Mundra, Nina J. Barnett, Linda J. Broadbelt, and John M. Torkelson. "Effects of Nanoscale Confinement and Interfaces on the Glass Transition Temperatures of a Series of Poly(n-methacrylate) Films." Australian Journal of Chemistry 60, no. 10 (2007): 765. http://dx.doi.org/10.1071/ch07234.

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We use fluorescence from dye-labelled polymer to measure the glass transition temperatures (Tgs) across single-layer films and near surfaces and silica interfaces in bilayer films for a series of poly(n-methacrylate)s. With nanoscale confinement, the average Tg across a film supported on silica increases for poly(methyl methacrylate) (PMMA), decreases for poly(ethyl methacrylate) (PEMA) and poly(propyl methacrylate), and is nearly invariant for poly(iso-butyl methacrylate) (PIBMA). These trends are consistent with the relative strengths of local perturbations to Tg caused by surfaces and substrates as measured in bilayer films. The substrate effect, which increases Tg via hydrogen-bonding interactions between the polymer and hydroxyl groups on the silica surface, is stronger than the free-surface effect in PMMA. The free-surface effect, which reduces Tg via a reduction in the required cooperativity of the glass transition dynamics, is stronger than the substrate effect in PEMA. The substrate and free-surface effects have similar strengths in perturbing the local Tg in PIBMA, resulting in a net cancellation of effects when measurements are made across single-layer films.
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46

HAGA, KOICH, TOETSU SHISHIDO, KAZUO NAKAJIMA, and TAKAHIRO MATSUNAGA. "HOMO-EPITAXIAL GROWTH ON ZnO SUBSTRATE BY MO-CVD USING (C5H7O2)2." Surface Review and Letters 14, no. 04 (August 2007): 783–87. http://dx.doi.org/10.1142/s0218625x07010263.

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High quality homo-epitaxial ZnO films were grown on Zn -terminated surfaces of ZnO (0001) single-crystal substrates with high-temperature annealing and Ar + ion etching. These films were prepared by low-pressure MO-CVD using zinc acetylacetonate ( C 5 H 7 O 2)2 and oxygen as source materials. High quality ZnO (0001) substrate was synthesized by the hydrothermal technique. The atomically flat surface without scratches was obtained by high temperature annealing at 800°C–1300°C in oxygen atmosphere. Ar + ion etching for the surface of ZnO substrates was critically important to the growth of ZnO films with good crystallinity. The epitaxial film and the ZnO substrate were characterized using reflection high-energy electron diffraction, atomic force microscope, and X-ray photoelectron spectroscopy.
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47

ACUÑA, SERGIO M., MARIA A. SANCHEZ, and PEDRO G. TOLEDO. "SURFACE FORCES AND ADHESION BETWEEN ELECTROLYTIC COPPER CATHODE SURFACES AND MICROSPHERE SURFACES OF GLASS AND POLYSTYRENE IN AQUEOUS ELECTROLYTE SOLUTIONS." International Journal of Nanoscience 03, no. 04n05 (August 2004): 499–510. http://dx.doi.org/10.1142/s0219581x04002309.

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Surface forces and adhesion between electrolytic copper cathode surfaces and sphere surfaces of glass and polystyrene were measured with an atomic force microscope (AFM) in water and in aqueous medium containing 104, 10-3 and 10-2 M sodium chloride at ambient temperature. Two types of copper surfaces were considered, oxidized and just-polished. Copper surfaces are submicroscopically rough and so at "contact", a film of intervening fluid separates substrate from probe. At close proximity, the interaction of the copper surfaces with either of the two probes is repulsive and such that extending and retracting force curves are essentially hysteresis-free. At higher separations, extending force curves for any probe-substrate combination were markedly repulsive and DLVO type. The higher the electrolyte concentration, the lower the range of the repulsive force. The system polystyrene-polished substrate displayed contact jumps for the higher electrolyte concentrations considered here, thus suggesting true adhesion between the surfaces. Strong and extremely long-ranged adhesive behavior were measured for the interaction between glass probes and oxidized copper substrates in low salt concentration solutions; at the origin are submicroscopic bubbles or cavities trapped between the surfaces and stabilized by the chemical heterogeneity of the interacting surfaces. A long-ranged, although weak, attractive interaction between polystyrene probes and just-polished copper substrates in aqueous salt solution belongs to the interacting surfaces although the intensity and range seems enhanced by the formation of bubbles.
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48

Ramli, J., D. N. Awang Sh’ri, N. A. Alang, Yusof Nor Imrah, and M. M. Mahat. "Effects of Surface Pretreatment to the Properties of Aluminum Oxide (Al2O3) Cutting Tool Coated Amorphous Graphite." Advanced Materials Research 463-464 (February 2012): 369–74. http://dx.doi.org/10.4028/www.scientific.net/amr.463-464.369.

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Hydrofluoric Acid (HF) and sand blasting have been incorporated together with chemical surface pretreatment (HF) for the surface pretreatment of the Al2O3 cutting tool. Amorphous graphite was deposited on the substrates by using PVD technique. Morphological observation by Scanning Electron Microscope (SEM), surface roughness and topography of the substrate by using Atomic Force Microscopy (AFM) was done in order to investigate the effect of surface pretreatment on the substrates. Critical load required in scratching the substrate’s surface after coating by different surface pretreatment was evaluated by microscratch testing. As-received micrograph has a continuous 45° direction based on horizontal line when the substrate was put in the chamber at the time the image was taken. Substrate with surface pretreatment shows non-uniform surface with peak and valley image. Coated surface micrograph shows amorphous graphite with cube in shape. Surface roughness and critical load for microscratch of sample was found increased with surface pretreatment both chemically and mechanically.
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49

Zhang, Y., H. Fan, W. Huang, and Y. Chen. "Droplets Atop a Wrinkled Substrate." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 224, no. 11 (April 27, 2010): 2459–67. http://dx.doi.org/10.1243/09544062jmes2069.

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Liquid droplets atop both isotropically and anisotropically patterned substrate surfaces are investigated experimentally. The patterns are realized by means of elastic wrinkling/buckling of a thin layer of gold coated atop polystyrene shape memory polymer. Static contact angles are measured, and images showing the shapes of droplets are captured. The results obtained from isotropically patterned substrates suggest that surface roughness has no apparent effect on the static contact angles in this study. However, atop anisotropically patterned substrates, both the static contact angles and shapes of droplets vary with the direction of wrinkles and size of droplets.
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50

O’Donnell, Mary Kate, and Stephen M. Deban. "The Effects of Roughness and Wetness on Salamander Cling Performance." Integrative and Comparative Biology 60, no. 4 (July 20, 2020): 840–51. http://dx.doi.org/10.1093/icb/icaa110.

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Synopsis Animals clinging to natural surfaces have to generate attachment across a range of surface roughnesses in both dry and wet conditions. Plethodontid salamanders can be aquatic, semi-aquatic, terrestrial, arboreal, troglodytic, saxicolous, and fossorial and therefore may need to climb on and over rocks, tree trunks, plant leaves, and stems, as well as move through soil and water. Sixteen species of salamanders were tested to determine the effects of substrate roughness and wetness on maximum cling angle. Substrate roughness had a significant effect on maximum cling angle, an effect that varied among species. Substrates of intermediate roughness (asperity size 100–350 µm) resulted in the poorest attachment performance for all species. Small species performed best on smooth substrates, while large species showed significant improvement on the roughest substrates (asperity size 1000–4000 µm), possibly switching from mucus adhesion on a smooth substrate to an interlocking attachment on rough substrates. Water, in the form of a misted substrate coating and a flowing stream, decreased cling performance in salamanders on smooth substrates. However, small salamanders significantly increased maximum cling angle on wetted substrates of intermediate roughness, compared with the dry condition. Study of cling performance and its relationship to surface properties may cast light onto how this group of salamanders has radiated into the most speciose family of salamanders that occupies diverse habitats across an enormous geographical range.
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