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}
{"title":"Cover image from I. P. Parkin and co-workers (Chem Vap. Deposition 2013, 19, 355)","authors":"","doi":"10.1002/cvde.201371011","DOIUrl":"https://doi.org/10.1002/cvde.201371011","url":null,"abstract":"<p>Four different TiO<sub>2</sub> thin films are prepared using AACVD, APCVD, and combined AACVD and APCVD in order to obtain films with new morphologies. The photocatalytic properties are assessed qualitatively by Resazurin and quantitatively using tris(hydroxymethyl)aminomethane.\u0000\u0000 <figure>\u0000 <div><picture>\u0000 <source></source></picture><p></p>\u0000 </div>\u0000 </figure></p>","PeriodicalId":10093,"journal":{"name":"Chemical Vapor Deposition","volume":"19 10-11-12","pages":""},"PeriodicalIF":0.0,"publicationDate":"2013-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/cvde.201371011","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91558273","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","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}
Zewen Zuo, Guanglei Cui, Yu Wang, Junzhuan Wang, Lin Pu, Yi Shi
{"title":"Substrate-thickness Dependence of Hydrogenated Microcrystalline Silicon Nucleation Rate on Amorphous Silicon Layer†","authors":"Zewen Zuo, Guanglei Cui, Yu Wang, Junzhuan Wang, Lin Pu, Yi Shi","doi":"10.1002/cvde.201307003","DOIUrl":"10.1002/cvde.201307003","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <p>The nucleation rate of hydrogenated microcrystalline silicon (µc-Si:H) films deposited by plasma-enhanced (PE)CVD on hydrogenated amorphous silicon (a-Si:H) substrates is investigated through structural and electrical characterization, with special attention paid to the initial growth stage of µc-Si:H films. It is found that the nucleation rate of µc-Si is dependent on the thickness of the a-Si:H substrate. The µc-Si:H film exhibits a rapid nucleation on a thin a-Si:H layer, leaving a thin incubation layer at the µc-Si/substrate interface. This substrate-thickness dependence of the nucleation rate is proposed to be correlated with the stress inside the a-Si:H layer. The high interfacial stress existing in the thin a-Si:H layer facilitates the formation of high concentration, strained Si-Si bonds, which are responsible for the rapid µc-Si nucleation. The thick a-Si:H layer relaxes the interfacial stress through the formation of islands in the Stranski-Krastanow (S-K) growth mode, while the intrinsic stress is still low, resulting in a long nucleation process allowing for the intrinsic compressive stress to be accumulated that is necessary for the µc-Si deposited on it.</p>\u0000 </section>\u0000 </div>","PeriodicalId":10093,"journal":{"name":"Chemical Vapor Deposition","volume":"19 10-11-12","pages":"363-366"},"PeriodicalIF":0.0,"publicationDate":"2013-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1002/cvde.201307003","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"51318590","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}