Journal of Material Sciences & Engineering最新文献

{"title":"Tuning Magnetic Properties of Thick CoFeB Film by Interlayer Coupling in Trilayer Structured Thin Films","authors":"Anabil Gayen, J. Aroutchelvane, K. Umadevi, P. Alagarsamy","doi":"10.4172/2169-0022.1000437","DOIUrl":"https://doi.org/10.4172/2169-0022.1000437","url":null,"abstract":"This study deals with tuning magnetic properties of a thick amorphous (a-)Co20Fe60B20 (CoFeB262) film by using interlayer magnetic coupling in trilayer structured films of [CoFeB262 (100 nm)/[Cr,Ta (x nm)]/CoFeB262 (y nm)] with y=2-50, xCr=0.75, 2 and xTa=1, 4. All the films are deposited directly on thermally oxidized Si substrate at ambient temperature using magnetron sputtering. The as-deposited a-CoFeB262 (100 nm) film exhibits magnetic stripe domain and transcritical hysteresis loop due to large effective magnetic anisotropy caused by stress induced during deposition of the films. On the other hand, the shape of magnetic hysteresis (M-H) loops in trilayer films transforms from transcritical to rectangular shaped one with enhanced remanence ratio (MR/MS) of ≥ 75% and single magnetization reversal behavior. This effectively reduces coercivity (HC) and field required to saturate magnetization (HS) in trilayer films. However, the changes in the loop shape and reductions in HC and HS depend strongly on x and y. Magnetic domain images obtained using Kerr microscopy in trilayer films show a rapid switching of large-sized domains along easy-axis and weak ripple domains along hard-axis. In addition, the magnetization reversal behavior along the hard-axis strongly depends on x(Cr,Ta). M-H loops obtained at different temperatures between 30 K and 300 K reveal no change in loop shape for trilayer films with small x and y, while the disappearance of shearing and formation of additional steps at low temperatures are observed for films with large x and y. The observed results are explained on the basis of change in interlayer coupling between CoFeB262 layers with x, y and temperature. Furthermore, these results clearly confirm that the magnetic properties of thick CoFeB262 film with stripe domain can easily be tuned into in-plane magnetization by this simple trilayer structured thin films.","PeriodicalId":16326,"journal":{"name":"Journal of Material Sciences & Engineering","volume":"25 1","pages":"1-10"},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81565417","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":"Silver Vanadium Oxide Nanomaterials: Controlled Synthesis by Hydrothermal Method and Efficient Photocatalytic Degradation of Atrazine and CV Dye","authors":"C. ChiingChang, Janah Shaya, F. Huan-Jung, C. Yi-Kuo, C. Han-ting, Chung‐Shin Lu","doi":"10.4172/2169-0022.1000407","DOIUrl":"https://doi.org/10.4172/2169-0022.1000407","url":null,"abstract":"Silver vanadium oxides have received remarkable attention in recent years because of their stability, suitable band gaps, and relatively superior photocatalytic abilities. This study synthesizes silver vanadates by the hydrothermal method and investigates their photocatalytic abilities for removing crystal violet (CV) and atrazine pollutants under visible-light irradiation. The as-prepared silver vanadates are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and UV-vis diffuse reflectance spectra (DRS). Crystal violet and atrazine could be successfully degraded in the presence of silver vanadate catalyst under visiblelight irradiation. The obtained results show complete degradation of crystal violet after 24 h, and over 97% of atrazine was degraded after 72 h of treatment. Moreover, the as-prepared silver vanadate materials show extremely high catalytic stability and maintain stable activity after three catalytic cycles. The scavenger study indicates that •O2− radicals are the main active species, while •OH and h+ play an assistant role in the degradation of CV and atrazine. Liquid chromatography coupled with electrospray ionization mass spectrometry is applied to the analysis of the samples coming from the photocatalytic degradation of CV and atrazine. Potential degradation pathways for atrazine are evaluated exhibiting two different degradation pathways including dechlorination-hydroxylation, alkylic-oxidationde- alkylation. The N-de-methylation of the CV dye takes place in a stepwise manner with the various N-de-methylated intermediate CV species. The excellent activity and photostability reveal that silver vanadate is a promising visiblelight- responsive photocatalyst for water and wastewater treatment.","PeriodicalId":16326,"journal":{"name":"Journal of Material Sciences & Engineering","volume":"54 1","pages":"1-11"},"PeriodicalIF":0.0,"publicationDate":"2017-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90245287","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":"Newly Developed Nickel-Boron Composite Surface Coatings with Pd Particles: Structural, Mechanical and Corrosion Properties","authors":"U. Waware, Hamouda Ams, Pradhan Ka","doi":"10.4172/2169-0022.1000406","DOIUrl":"https://doi.org/10.4172/2169-0022.1000406","url":null,"abstract":"Ni-B and Ni-B-Pd composite coatings have been electrodeposited from an aqueous electrolyte using direct current. The Ni-B composite coating has been observed to be dense, smooth, and shows a globular, cluster of grains type morphology. On the other hand, the Ni-B-Pd composite coating is observed to be porous, highly rough and shows stacked crystal type morphology. The addition of palladium has significantly improved the crystallite size of the coating. From DSC analysis, it is observed that the Ni-B-Pd composite coating is thermodynamically more stable than the Ni-B composite coating. In spite of larger grain size and higher roughness the Ni-B-Pd coating is observed to exhibit higher hardness (≈40% higher) and elastic modulus (≈70% higher) than that of the Ni-B composite coating. Also, it has been observed to possess better protective property (almost three times) than that of the Ni-B composite coating.","PeriodicalId":16326,"journal":{"name":"Journal of Material Sciences & Engineering","volume":"26 1","pages":"1-7"},"PeriodicalIF":0.0,"publicationDate":"2017-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75797734","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":"Dilemma between Physics and ISO Elastic Indentation Modulus","authors":"G. Kaupp","doi":"10.4172/2169-0022.1000402","DOIUrl":"https://doi.org/10.4172/2169-0022.1000402","url":null,"abstract":"This paper challenges the ISO standard 14577 that determines the elastic indentation modulus by violating the first energy law, and omitting easily detected phase change onsets as well as initial surface effects under load. The double iteration for incorrect fitting indentation modulus to Hook's law Young's modulus of a standard with up to 11 free parameters must be cancelled and discontinued. The iterative evaluation of the elastic modulus Er-ISO can by far not be reproduced by iteration-free direct calculation of Er, when using the underlying formulas for S, hc, Ahc, and ε. For cubic aluminium the divergence amounts to a factor of 3.5 or 3.1, respectively (both smaller for the non-iterated calculations). Every interpretation of indentation moduli as single unidirectional \"Young's moduli\" is false. They are mixtures from all directions and include shear moduli. The three different packing diagrams of body centered cubic α-iron exemplify the mixture of three independent Young's moduli (and thus also three shear moduli) even in this simple but already anisotropic case. More linear moduli ensue in lower symmetry crystals as exemplified with α-quartz. The first physical indentation modulus is deduced by removal of the physical errors of Er-ISO, or after indenter compliance correction EISO. Ephys does no longer violate the energy law. Five face-dependent elastic indentation moduli of α-quartz at the obsolete Er-ISO level and two tensional Hook-law Young's moduli are compared with all of its six resonance ultrasound spectroscopy (RUS) evaluated Young's moduli, and with the bulk modulus. The dilemma between ISO and physics is particularly detrimental, as EISO is used for the calculation of very frequently applied mechanical parameters. These propagate the errors into failure risks of falsely calculated materials with severe violation of the basic energy law and other physical laws for daily life. Difficulties with the urgent settlement by new ISO standards are discussed. First suggestions for the use of Ephys, or Sphys, or eventually measured bulk modulus K are made. This should be urgently evaluated and discussed. *Corresponding author: Gerd Kaupp, University of Oldenburg, Diekweg 15, D-26188 Edewecht, Germany, Tel: 4944868386; Fax: 4486920704; E-mail: gerd.kaupp@uni-oldenburg.de Received October 28, 2017; Accepted December 11, 2017; Published December 21, 2017 Citation: Kaupp G (2017) Dilemma between Physics and ISO Elastic Indentation Modulus. J Material Sci Eng 6: 402. doi: 10.4172/2169-0022.1000402 Copyright: © 2017 Kaupp G. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.","PeriodicalId":16326,"journal":{"name":"Journal of Material Sciences & Engineering","volume":"1 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2017-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88597581","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":"The Effect of Cu on the Decomposition of Al-Zn-Mg-(Cu) Alloys","authors":"J. Lamb, Sanders Jr. Th","doi":"10.4172/2169-0022.1000404","DOIUrl":"https://doi.org/10.4172/2169-0022.1000404","url":null,"abstract":"A series of experimental Al-Zn-Mg-(Cu) alloys with a semi-constant Zn:Mg ratio were produced via hot rolling. The effects of Cu in these alloys on the activation energy for precipitation, the response to natural aging, the size of the precipitate free zone, and the corrosion resistance were investigated.","PeriodicalId":16326,"journal":{"name":"Journal of Material Sciences & Engineering","volume":"88 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2017-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74470967","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":"An Electrical Model for Off-Plane Nano Needle Array Electrodes in Intracellular Signal Measurement in Biological Environments","authors":"N. Mehmood, A. Hariz","doi":"10.4172/2169-0022.1000405","DOIUrl":"https://doi.org/10.4172/2169-0022.1000405","url":null,"abstract":"Electrical signals emanating from biological cells can convey clinical information on the functionality thereof. However, measurement of such small signals caused primarily by ionic activity inside the cell, known as action potential, poses a great challenge to biomedical scientists. The electrical signals of the biological cells result from exchange of ions through the cell membrane. The characteristics of action potentials may reveal a great deal of information about the causes and symptoms of abnormal cell behaviour. Hence, it is imperative to capture high quality action potentials through the use of nano-sensors from within the cell. Recently, developments in silicon nanowires (SiNW) fabrication techniques have demonstrated a great potential for them to be used as nano-electrodes. Largescale assembly and integration of addressable complementary silicon nanowires arrays have been demonstrated for multiplexed biosensor arrays. The fabrication process resulted in a high-yield, high performance devices arrays for chemical and biological detection. In this paper, we seek to model the electrical interface that is responsible for recording the biological signals. We present electrical equivalent circuits that model the boundary between the biological cell and the nanowire electrode. Impedance measurement curves of nanowires for various sizes of length and diameter have also been presented and discussed. The impedance graphs show a hyperbolic dependence of resistance on length and diameter of nanowires. This non-linear behaviour may be mitigated in software algorithms when interpreting the measured cell signals.","PeriodicalId":16326,"journal":{"name":"Journal of Material Sciences & Engineering","volume":"9 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2017-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83897203","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":"Synthesis and Evaluation of Olivine Nanosheets from Layered Ammonium Iron Phosphate Monohydrate","authors":"Masakazu Togo, A. Nakahira","doi":"10.4172/2169-0022.1000403","DOIUrl":"https://doi.org/10.4172/2169-0022.1000403","url":null,"abstract":"The synthesis of novel microstructured LiFePO4 with advantageous nanosheets for Li ion conductivity was attempted. Using layered NH4FePO4•H2O as raw material, LiFePO4 nanosheet was synthesized by the hydrothermal process in LiCl solution. Prepared NH4FePO4•H2O was several tens micrometer sized sheet with about 200 nm in thickness. As Li ion resource, various LiCl solution like deionized water, ethanol, and ethylene glycol were prepared through subsequent hydrothermal process and the effect of a kind of solvents for LiCl solution on the microstructure of products treated by the hydrothermal process was investigated for LiFePO4 nanosheets synthesis. The products of LiFePO4 nanosheet were characterized by XRD, SEM, TEM, FT-IR and ICP. Regardless of a kind of solvents, LiFePO4 nanosheet was composed of arranged nano-blocks, although the size and morphology of nano-blocks was different in each solvent.","PeriodicalId":16326,"journal":{"name":"Journal of Material Sciences & Engineering","volume":"64 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2017-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85666620","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":"Fatigue Resistance Study of Quenched and Tempered High-Strength Steel Submitted to Low Intensity Shot Peening Treatments with Different Types of Shots","authors":"E. Segurado, Belzunce Fj, I. FernándezPariente","doi":"10.4172/2169-0022.1000401","DOIUrl":"https://doi.org/10.4172/2169-0022.1000401","url":null,"abstract":"The aim of this research is to study the fatigue life enhancement produced in quenched and tempered AISI4340 steel with a tensile strength of 2000 MPa after being submitted to shot peening surface treatments. These treatments generate compressive residual stress fields in a superficial layer of the material at the same time as inducing some kind of damage on the surface. Different kind of projectiles were chosen to perform the treatment (ceramic and steel shots), studying the way these affected the fatigue life of the specimens. \u0000The surface topography of the samples was analysed using a roughness tester and by means of scanning electron microscopy (SEM). The compressive residual stress profile induced by these treatments was measured using X-ray diffraction (XRD) plus electro-polishing. The fatigue behaviour of the treated samples was subsequently studied by means of 4-point rotating bending tests and their fracture surfaces were analysed using SEM. \u0000The best fatigue performance was obtained after shot peening with ceramic beads under 8A Almen intensity. The main difference in relation to the treatment performed under the same intensity but using steel cut wire shots was the much lower surface damage induced by the impacts with the ceramic shots compared with the cut wire projectiles, which in turn is justified by the greater geometric perfection and hardness of the former. Furthermore, fatigue specimens shot peened with ceramic beads under 8A intensity always gave rise to internal fatigue crack initiation, which took place outside the zone subjected to residual compressive stresses. Moreover, fatigue initiation was always linked to the presence of hard and rigid alumina inclusions, which acted as microstructural stress concentrators.","PeriodicalId":16326,"journal":{"name":"Journal of Material Sciences & Engineering","volume":"46 1","pages":"1-7"},"PeriodicalIF":0.0,"publicationDate":"2017-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88156923","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":"Effect of Heat Treatment of Cu-Al-Be Shape Memory Alloy on Microstructure, Shape Memory Effect and Hardness","authors":"J. Al-haidary, A. M. Mustafa, A. A. Hamza","doi":"10.4172/2169-0022.1000398","DOIUrl":"https://doi.org/10.4172/2169-0022.1000398","url":null,"abstract":"Cu-13Al-0.545Be shape memory alloy are heat treatment at different temperature and time. The microstructure of alloy after heat treatment at 850°C, 650°C and aging at 150°C ,450°C and 550°C for 2, 4 and 6 h study by optical microscope and X-ray diffraction. Bending test is use to show effect of heat treatment on super-elastic and shape memory effect. \u0000Micro hardness test used to show effect of heat treatment on micro hardness .shape memory effect increase at heat treatment 650°C and aging at 150°C, while at 450°C and 550°C will decrease because precipitate formation rate rises with increase in temperature and time. The hardness and precipitates in the alloy increases with increasing ageing duration. Higher ageing temperature avoids the imperfection by moving and filling the empty space thereby hardens the alloy.","PeriodicalId":16326,"journal":{"name":"Journal of Material Sciences & Engineering","volume":"256 1","pages":"1-7"},"PeriodicalIF":0.0,"publicationDate":"2017-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77535134","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":"Nanofibers for High Efficiency Filtration","authors":"Prakash Khude","doi":"10.4172/2169-0022.1000399","DOIUrl":"https://doi.org/10.4172/2169-0022.1000399","url":null,"abstract":"Nanofiber is a broad phrase generally referring to a fibre with a diameter less than 1 micron. While glass fibres have existed in the sub-micron range for some time and polymeric meltblown fibres are just beginning to break the micron barrier, sub-half-micron diameters have been used for air filtration in commercial, industrial and defence applications for more than twenty years. They have been shown to deliver improved filter life, increased contaminate holding capacity and enhanced filtration efficiency. Small fibres in the sub-micron range, in comparison with larger ones, are well known to provide higher filter efficiency at the same pressure drop in the interception and inertial impaction stages of the filtration process. In particular, nanofibers provide marked increases in filtration efficiency at relatively small (and in some cases immeasurable) decreases in permeability. Nanofiber filter media have enabled new levels of filtration performance in several diverse applications with a broad range of environments and contaminants. While nano fibre size lead to a higher pressure drop, interception and inertial impaction efficiencies will increase faster, and therefore more than compensating for the rise in pressure drop. Thus, in the particle size of interest, i.e. from sub-micron upwards, better filter efficiency can be achieved at the same pressure drop, or conversely, the same filter efficiency at a lower pressure drop can be achieved with nanofibres. This paper will discuss a process for making nanofibers, as well as the benefits, limitations, construction, and applications of filters using nanofiber media.","PeriodicalId":16326,"journal":{"name":"Journal of Material Sciences & Engineering","volume":"31 1","pages":"1-10"},"PeriodicalIF":0.0,"publicationDate":"2017-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91249615","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}