Bartek Wierzba, Katarzyna Tkacz-Śmiech, Andrzej Nowotnik, Kamil Dychtoń
{"title":"Aluminizing of Nickel Alloys by CVD. The Effect of HCl Flow†","authors":"Bartek Wierzba, Katarzyna Tkacz-Śmiech, Andrzej Nowotnik, Kamil Dychtoń","doi":"10.1002/cvde.201307090","DOIUrl":"10.1002/cvde.201307090","url":null,"abstract":"<div>\u0000 \u0000 <section>\u0000 \u0000 <p>The solid-state diffusion in binary and ternary systems is overall treated and modeled using the bi-velocity method. The mathematical formulation is given, and the boundary conditions discussed. The model allows the calculation of concentration profiles, spatial distribution of the entropy production rate, and diffusion path. The last two can be used to identify the phases present in the diffusion zone of the ternary system, and determine the thicknesses of the respective layers. The model is applied for the first time to simulate diffusion during aluminization of nickel and its super-alloys, MAR-M200 + Hf and CMSX-4, and the predictions are compared with the results of the experiments performed by the authors. The results give a new quantitative explanation of the high-active and low-active regimes of aluminization. It is, in particular, confirmed that the high-active and low-active regimes of nickel aluminization can be carried out by a variation of the HCl/H<sub>2</sub> flow ratio. The most important, and a brand new, result concerns the entropy production rate. It is shown that its maxima coincidence with the two-phase zone boundaries in real space, which gives new insight into the modeling of the diffusion in ternary systems.</p>\u0000 </section>\u0000 </div>","PeriodicalId":10093,"journal":{"name":"Chemical Vapor Deposition","volume":"20 1-2-3","pages":"80-90"},"PeriodicalIF":0.0,"publicationDate":"2014-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/cvde.201307090","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"51320030","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sanjayan Sathasivam, Andreas Kafizas, Sapna Ponja, Nicholas Chadwick, Davinder S. Bhachu, Salem M. Bawaked, Abdullah Y. Obaid, Shaeel Al-Thabaiti, Sulaiman N. Basahel, Claire J. Carmalt, Ivan P. Parkin
{"title":"Combinatorial Atmospheric Pressure CVD of a Composite TiO2/SnO2 Thin Film†","authors":"Sanjayan Sathasivam, Andreas Kafizas, Sapna Ponja, Nicholas Chadwick, Davinder S. Bhachu, Salem M. Bawaked, Abdullah Y. Obaid, Shaeel Al-Thabaiti, Sulaiman N. Basahel, Claire J. Carmalt, Ivan P. Parkin","doi":"10.1002/cvde.201307081","DOIUrl":"10.1002/cvde.201307081","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <p>Combinatorial atmospheric pressure (cAP)CVD is used to deposit a film of graded composition from mainly TiO<sub>2</sub> to TiO<sub>2</sub>/SnO<sub>2</sub> to mainly SnO<sub>2</sub>. This is the first cAPCVD study of a TiO<sub>2</sub>/SnO<sub>2</sub> system. The thin film is characterized using a range of techniques such as X-ray diffraction (XRD), wavelength dispersive X-ray (WDX) spectroscopy, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and ultra violet-visible (UV-vis) spectroscopy. It is found that, at various positions on the film, there are intimate compositions of TiO<sub>2</sub> and SnO<sub>2</sub>. The photocatalytic activity is examined via the degradation of a Resazurin-based ‘intelligent ink’ under 365 nm wavelength irradiation. The change in the concentration of the dye can be monitored by digital imaging alone. The results show how TiO<sub>2</sub>-rich regions are photocatalytically active, producing a maximum formal quantum yield of 3.32 × 10<sup>−4</sup> molecules per absorbed photon. The sheet resistance is determined using a four-point probe via the van der Pauw method. The conductivity is highest in the SnO<sub>2</sub>-rich and thicker regions of the film, however some of the intimate composite regions of TiO<sub>2</sub>/SnO<sub>2</sub> show both conductivity and photocatalytic activity.</p>\u0000 </section>\u0000 </div>","PeriodicalId":10093,"journal":{"name":"Chemical Vapor Deposition","volume":"20 1-2-3","pages":"69-79"},"PeriodicalIF":0.0,"publicationDate":"2014-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/cvde.201307081","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"51319567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kyung-Hyun Choi, Kamran Ali, Chang Young Kim, Nauman Malik Muhammad
{"title":"Characterization of Al2O3 Thin Films Fabricated at Low Temperature via Atomic Layer Deposition on PEN Substrates†","authors":"Kyung-Hyun Choi, Kamran Ali, Chang Young Kim, Nauman Malik Muhammad","doi":"10.1002/cvde.201307082","DOIUrl":"10.1002/cvde.201307082","url":null,"abstract":"<div>\u0000 \u0000 <section>\u0000 \u0000 <p>Good quality Al<sub>2</sub>O<sub>3</sub> thin films are deposited on polyethylene naphthalate (PEN) substrates through atomic layer deposition (ALD) at temperatures as low as 35 °C. Trimethylaluminum [TMA, Al(CH<sub>3</sub>)<sub>3</sub>] and water are used as precursors in the present study. Growth rates of 1.14 Å per cycle are observed at 35 °C, while the average arithmetic roughness (<i>Ra</i>) of the film is 0.86 nm. X-ray photoelectron spectroscopy (XPS) analysis confirms the high purity of the grown films with no carbon contamination. Good insulating properties are observed for the films and optical transmittance of more than 90% is recorded in the visible region.</p>\u0000 </section>\u0000 </div>","PeriodicalId":10093,"journal":{"name":"Chemical Vapor Deposition","volume":"20 4-5-6","pages":"118-124"},"PeriodicalIF":0.0,"publicationDate":"2014-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/cvde.201307082","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"51319599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Aravind Suresh, Daniel Anastasio, Daniel D. Burkey
{"title":"Potential of Hexyl Acrylate Monomer as an Initiator in Photo-initiated CVD†","authors":"Aravind Suresh, Daniel Anastasio, Daniel D. Burkey","doi":"10.1002/cvde.201304322","DOIUrl":"10.1002/cvde.201304322","url":null,"abstract":"<p>The potential of hexyl acrylate as an initiator in photo-initiated (pi) CVD is explored by demonstrating its auto-polymerization under ultraviolet (UV) radiation of wavelength 254 nm. Deposition of poly(hexyl acrylate) films on silicon substrates proceeds at high rates, approaching 1.7 µm min<sup>−1</sup>, at a stage temperature of 12.1°C, and the process is observed to be adsorption controlled.</p>","PeriodicalId":10093,"journal":{"name":"Chemical Vapor Deposition","volume":"20 1-2-3","pages":"5-7"},"PeriodicalIF":0.0,"publicationDate":"2013-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/cvde.201304322","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"51318372","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yaseen Elkasabi, Aftin M. Ross, Jonathan Oh, Michael P. Hoepfner, H. Scott Fogler, Joerg Lahann, Paul H. Krebsbach
{"title":"Design Strategies for Reduced-scale Surface Composition Gradients via CVD Copolymerization†","authors":"Yaseen Elkasabi, Aftin M. Ross, Jonathan Oh, Michael P. Hoepfner, H. Scott Fogler, Joerg Lahann, Paul H. Krebsbach","doi":"10.1002/cvde.201307057","DOIUrl":"10.1002/cvde.201307057","url":null,"abstract":"<div>\u0000 \u0000 <section>\u0000 \u0000 <p>A new method for generating and modeling reduced-scale copolymer gradients by CVD is reported. By exploiting diffusion through confined channels, functionalized [2.2]paracyclophanes are copolymerized into their poly(<i>p</i>-xylylene) (PPX) analogues as a composition gradient. Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) are used to verify the gradient composition profiles. Gradients are deposited on both flat substrates and 3-dimensional cylinders. Both the thickness and compositional profiles are fitted to a diffusion-based model using realistic physical parameters. The derived equation can be generalized and optimized for any copolymerization gradient through a confined geometry, thus allowing for broad applicability to other copolymer systems.</p>\u0000 </section>\u0000 </div>","PeriodicalId":10093,"journal":{"name":"Chemical Vapor Deposition","volume":"20 1-2-3","pages":"23-31"},"PeriodicalIF":0.0,"publicationDate":"2013-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/cvde.201307057","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"51318869","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Facile and Fast Deposition of Amorphous TiO2 Film under Atmospheric Pressure and at Room Temperature, and its High Photocatalytic Activity under UV-C Light†","authors":"Zhi-Guang Sun, Xiao-Song Li, Xiaobing Zhu, Xiao-Qing Deng, Da-Lei Chang, Ai-Min Zhu","doi":"10.1002/cvde.201307088","DOIUrl":"10.1002/cvde.201307088","url":null,"abstract":"<div>\u0000 \u0000 <section>\u0000 \u0000 <p>A facile and fast CVD method for the deposition of TiO<sub>2</sub> films, under atmospheric pressure and at room temperature, onto glass and polyethylene terephthalate (PET) substrates is explored. The hydrolysis reaction of titanium tetraisopropoxide (TTIP) is employed for the deposition of TiO<sub>2</sub> film, and the corresponding deposition rate determined. The surface morphology of the as-deposited TiO<sub>2</sub> films is observed by scanning electron microscopy (SEM) and atomic force microscopy (AFM). In order to confirm the structure, composition, and optical properties of the films, X-ray diffraction (XRD), Raman spectroscopy (RS), Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and UV-Vis absorption spectroscopy are employed. The as-deposited TiO<sub>2</sub> films are amorphous with a band gap energy of around 3.42 eV and rich in surface OH groups, which exhibit very high photocatalytic activity for complete oxidation of HCHO in simulated air under UV-C irradiation.</p>\u0000 </section>\u0000 </div>","PeriodicalId":10093,"journal":{"name":"Chemical Vapor Deposition","volume":"20 1-2-3","pages":"8-13"},"PeriodicalIF":0.0,"publicationDate":"2013-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/cvde.201307088","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"51319891","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sergey Bogdanov, Anatoly Vikharev, Aleksei Gorbachev, Anatoly Muchnikov, Dmitry Radishev, Nikolai Ovechkin, Vladimir Parshin
{"title":"Growth-rate Enhancement of High-quality, Low-loss CVD-produced Diamond Disks Grown for Microwave Windows Application†","authors":"Sergey Bogdanov, Anatoly Vikharev, Aleksei Gorbachev, Anatoly Muchnikov, Dmitry Radishev, Nikolai Ovechkin, Vladimir Parshin","doi":"10.1002/cvde.201307058","DOIUrl":"10.1002/cvde.201307058","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <p>The effect of nitrogen addition on the growth rate, quality, and properties of polycrystalline diamond grown by microwave plasma assisted (MPA)CVD is investigated. Two series of experiments are performed at two different microwave power densities (40 and 110 W cm<sup>-3</sup>) using a 2.45 GHz cylindrical microwave reactor. The results show that the beneficial effect of nitrogen is more distinct at higher microwave power densities. To investigate the properties of polycrystalline diamond grown with nitrogen addition, a thick diamond disk of 50 mm diameter is grown with an addition of 50 ppm nitrogen using a 2.45 GHz ellipsoidal microwave reactor. The grown diamond disk has a thermal conductivity of 17.3 W cm<sup>-1</sup> K<sup>-1</sup> and dielectric loss tangent of 3.7 × 10<sup>-5</sup> at a frequency of 170 GHz, and its parameters are suitable for application in microwave windows (e.g., gyrotron windows). Our results indicate that it is possible to achieve the increased (by a factor of 2.5) growth rates by nitrogen addition without significant degradation of diamond quality, and properties such as thermal conductivity and dielectric loss tangent.</p>\u0000 </section>\u0000 </div>","PeriodicalId":10093,"journal":{"name":"Chemical Vapor Deposition","volume":"20 1-2-3","pages":"32-38"},"PeriodicalIF":0.0,"publicationDate":"2013-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/cvde.201307058","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"51318924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Stephan Schulz, Georg Bendt, Wilfried Assenmacher, Daniel Sager, Gerd Bacher
{"title":"Low-Temperature MOCVD of Crystalline Ga2O3 Nanowires using tBu3Ga†","authors":"Stephan Schulz, Georg Bendt, Wilfried Assenmacher, Daniel Sager, Gerd Bacher","doi":"10.1002/cvde.201307060","DOIUrl":"10.1002/cvde.201307060","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <p>Crystalline Ga<sub>2</sub>O<sub>3</sub> nanowires are synthesized via an Au-catalyzed, as well as a self-catalyzed, growth by a low-temperature metal-organic (MO)CVD process using <sup><i>t</i></sup>Bu<sub>3</sub>Ga as a novel Ga source. Morphology, elemental composition, and crystallinity of the resulting nanowires are analyzed by scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and selected area electron diffraction (SAED). Photoluminescence (PL) spectra of the Ga<sub>2</sub>O<sub>3</sub> nanowires show efficient defect-luminescence in the visible and UV ranges with blue and green emission peaks at 430 nm and 512 nm, respectively, at room temperature.</p>\u0000 </section>\u0000 </div>","PeriodicalId":10093,"journal":{"name":"Chemical Vapor Deposition","volume":"19 10-11-12","pages":"347-354"},"PeriodicalIF":0.0,"publicationDate":"2013-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/cvde.201307060","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"51318968","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}