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Effect of Decreasing of Cobalt Content in Properties for Diamond∕Cemented Carbide Tools

A. Waratta, M. Hamdi, and T. Ariga

AIP Conf. Proc. 1217, pp. 1-5; doi:http://dx.doi.org/10.1063/1.3377813 (5 pages)

Online Publication Date: 30 March 2010

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Powder metallurgy plays a role in manufacturing such as automotive and cutting tool applications. Diamond∕cemented carbide tools are also made from this technique. Diamond particle and other matrix materials were employed in this study. The purpose is to investigate the physical and mechanical properties of different Cobalt (Co) content samples by using Taguchi’s method. The materials used in the experiments were mixed by using a ball‐mill machine. The mixed powders were pressed by conventional method. Then the green samples were sintered in a vacuum furnace. After reaching 500° C, the samples were sintered with Argon (Ar) gas. The sintered samples were investigated density by immersion method, porosity by water saturation method, and hardness by Vicker hardness tester. It was found that with 59.5% Co content, plain diamond type, sintering temperature of 950° C, sintering time of 40 minutes, and pressure of 625 MPa, density, porosity, and hardness got the best result in this study. From the Taguchi’s analysis, the significant factors effected the performance were composition, sintering temperature, and sintering time.

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81.20.Ev	Powder processing: powder metallurgy, compaction, sintering, mechanical alloying, and granulation
81.05.Je	Ceramics and refractories (including borides, carbides, hydrides, nitrides, oxides, and silicides)
81.05.ug	Diamond
81.65.Kn	Corrosion protection

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The Effects of Different Precursor Milling Processes on the Phase Evolution of Nanocrystalline Barium Hexaferrite

A. Ataie, K. Sheikhi‐Moghaddam, S. F. Kashani‐Bozorg, and J. Sargheini

AIP Conf. Proc. 1217, pp. 6-10; doi:http://dx.doi.org/10.1063/1.3377891 (5 pages)

Online Publication Date: 30 March 2010

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Nano‐crystalline barium hexaferrite was synthesized using a coupled mechano‐chemical processing (co‐precipitation∕mechanical milling); initially co‐precipitated product prepared from aqueous solutions of iron and barium chlorides with a Fe∕Ba molar ratio of 11 was mechanically milled employing two different milling processes (low energy jar mill and high energy planetary mill). The non‐milled and milled co‐precipitated materials were then annealed at various temperatures. The thermal properties, phase composition and morphology of samples were investigated. XRD and DTA∕TGA results showed that formation of barium hexaferrite occurs at relatively low temperature using planetary milling technique. Also, no BaFe₂O₄ (intermediate non magnetic phase) was detected by XRD in the milled products. SEM studies exhibited that the mean particle size of barium hexaferrite dramatically increases with increasing annealing temperature from 700 to 1100° C.

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81.07.Bc	Nanocrystalline materials
81.20.Ev	Powder processing: powder metallurgy, compaction, sintering, mechanical alloying, and granulation
61.05.C-	X-ray diffraction and scattering
68.37.Hk	Scanning electron microscopy (SEM) (including EBIC)
81.10.Dn	Growth from solutions
81.10.Fq	Growth from melts; zone melting and refining
81.15.Lm	Liquid phase epitaxy; deposition from liquid phases (melts, solutions, and surface layers on liquids)

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Characterization of MOSFET‐like Carbon Nanotube Field Effect Transistor

A. M. Hashim, H. H. Ping, and C. Y. Pin

AIP Conf. Proc. 1217, pp. 11-18; doi:http://dx.doi.org/10.1063/1.3377796 (8 pages)

Online Publication Date: 30 March 2010

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The downscaling of metal‐oxide‐semiconductor field‐effect transistor (MOSFET) has been taking place since decades ago for enhancing circuit functionality and also for extending Moore’s Law. As the downsizing of MOSFET continues, it faces the challenge of size limitation and severe short‐channel effects (SCEs) appear to affect the performance of nanoscale‐MOSFET. Some novel nanoelectronic devices are proposed, hoping to overcome those MOSFET limitations. One of the novel nanoelectronic devices is carbon nanotube field‐effect transistor (CNFET). Simulation work using MATLAB based programming on CNFET is carried out to investigate the dependence of current‐voltage (I‐V) characteristics on various carbon nanotube (CNT) diameters, insulator thicknesses and temperatures as well as their transconductances, gate delays and energy delay products (EDPs). The simulation results are presented and then compared with conventional nanoscale‐MOSFET. It seems to provide better performance than MOSFET in term of high speed capability and lower switching power consumption.

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85.30.Tv	Field effect devices
81.07.De	Nanotubes
85.30.Pq	Bipolar transistors
72.20.Ee	Mobility edges; hopping transport

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Harmonic Responses in 2DEG AlGaAs∕GaAs HEMT Devices Due to Plasma Wave Interaction

A. M. Hashim, S. Kasai, H. Hasegawa, and Q. I. Alias

AIP Conf. Proc. 1217, pp. 19-25; doi:http://dx.doi.org/10.1063/1.3377812 (7 pages)

Online Publication Date: 30 March 2010

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Plasma waves are oscillations of electron density in time and space, and in deep submicron field effect transistors, typical plasma frequencies, ω_p, lie in the terahertz range and do not involve any quantum transitions. Hence, using plasma wave excitation for detection and∕or generation of THz oscillations is a very promising approach. In this paper, the investigation of plasma wave interaction between the plasma waves propagating in a short‐channel High‐Electron‐Mobility Transistor (HEMT) and the radiated electromagnetic waves was carried out. Experimentally, we have demonstrated the detection of the terahertz (THz) radiation by an AlGaAs∕GaAs HEMT up to third harmonic at room temperature and their resonant responses show very good agreement with the calculated results.

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85.30.Tv	Field effect devices
72.20.Ee	Mobility edges; hopping transport
84.40.Az	Waveguides, transmission lines, striplines
52.58.Lq	Z-pinches, plasma focus, and other pinch devices

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Destructive and Non‐Destructive Analysis Techniques for Failure Detection of QFN Packages

M. N. Adhila, S. Wedianti, W. S. W. M. Suhaimi, and I. Aishah

AIP Conf. Proc. 1217, pp. 26-32; doi:http://dx.doi.org/10.1063/1.3377828 (7 pages)

Online Publication Date: 30 March 2010

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One of the latest developments in packaging technology is the QFN (Quad Flat Non‐Lead) packages, which is both a chip scale package and plastic encapsulated package with lead pad at the bottom. In this paper, different type of commercial QFN single die packages were characterized by using destructive and non‐destructive techniques. Non‐destructive techniques such as Scanning Acoustic Microscope (SAM) and X‐Ray analysis were used to observe package cracking, delamination and other failure mode. Application of SAM include detection of delaminations between lead frame, die face, paddle, heat sink, cracks and plastic encapsulant. In comparison to other techniques, SAM is sensitive to detect beneath the surface of devices which would be inaccessible otherwise by both conventional optical and electron microscopy inspection methods. Destructive technique such as Field Emission Electron Microscopy (FESEM) was implemented to address the failures of the QFN single die packages such as die cracking, lifted ball bonds and other failure mode.

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81.70.Cv	Nondestructive testing: ultrasonic testing, photoacoustic testing
43.58.Ls	Acoustical lenses and microscopes
85.40.Hp	Lithography, masks and pattern transfer
68.37.Hk	Scanning electron microscopy (SEM) (including EBIC)
81.05.Lg	Polymers and plastics; rubber; synthetic and natural fibers; organometallic and organic materials

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Comparative Study of Substituted LiMn_(2−x)FexO₄ via Sol‐Gel Route

A. F. M. Fadzil, N. S. A. Puada, R. H. Y. Subban, and N. Kamarulzaman

AIP Conf. Proc. 1217, pp. 33-36; doi:http://dx.doi.org/10.1063/1.3377840 (4 pages)

Online Publication Date: 30 March 2010

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In this work, LiMn_1.9Fe_0.1O₄ and LiMn_1.5Fe_0.5O₄ were prepared by sol‐gel method according to proper stoichiometric ratio. It is then calcined at 850° C for 24 hours. Characterization studies of final products were done using XRD, FESEM, cyclic voltammetry (CV) and charge−discharge characteristics. Phase composition of the samples were studied from the XRD patterns obtained. For the microstructural studies, FESEM results show an average particle size of the bulk particles. From the charge−discharge characteristics, it showed that these samples exhibited good discharge capacities.

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81.10.Dn	Growth from solutions
81.10.Fq	Growth from melts; zone melting and refining
81.15.Lm	Liquid phase epitaxy; deposition from liquid phases (melts, solutions, and surface layers on liquids)
61.05.cp	X-ray diffraction
61.66.Bi	Elemental solids
61.66.Dk	Alloys
68.37.Hk	Scanning electron microscopy (SEM) (including EBIC)

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SEM and XRD Characterization of ZnO Nanostructured Thin Films Prepared by Sol‐Gel Method with Various Annealing Temperatures

S. Amizam, N. Abdullah, H. A. Rafaie, and M. Rusop

AIP Conf. Proc. 1217, pp. 37-41; doi:http://dx.doi.org/10.1063/1.3377848 (5 pages)

Online Publication Date: 30 March 2010

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ZnO thin films were fabricated by the sol‐gel method using Zn(CH₃COO)₂.2H₂O (zinc acetate) as starting material. A homogenous and stable solution was prepared by dissolving the zinc acetate in a solution of ethanol and ethanolamine. Deposition of ZnO solution on Si substrate was performed by spin‐coating technique and annealed at various temperatures from 200° C to 600° C. The surface morphologies and structural properties of the obtained product were investigated by scanning electron microscopy (SEM) and X‐ray diffraction (XRD). SEM analysis showed that the surface boundaries of ZnO thin films were decreased with the increasing of annealing temperature. X‐ray analysis showed that the crystallinity of ZnO thin films increased with increasing annealing temperature. The effect of annealing temperature of ZnO thin films was studied.

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81.07.Bc	Nanocrystalline materials
81.10.Dn	Growth from solutions
81.10.Fq	Growth from melts; zone melting and refining
81.15.Lm	Liquid phase epitaxy; deposition from liquid phases (melts, solutions, and surface layers on liquids)
68.37.Hk	Scanning electron microscopy (SEM) (including EBIC)
61.05.cp	X-ray diffraction
81.15.Aa	Theory and models of film growth

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Characterisation of Semi‐Metallic Brake Pads using Brake Dynamometer

R. J. Talib, E. Othman, and R. Kasiran

AIP Conf. Proc. 1217, pp. 42-46; doi:http://dx.doi.org/10.1063/1.3377860 (5 pages)

Online Publication Date: 30 March 2010

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Friction materials are complex mix of fibres, modifiers, additives, fillers and a binder resin which holds them together and are composed of between 5 and 20 elements in the composition. Each element has its own function and changing any element or its weight percentage will change the friction material properties. Besides, there is no rule of thumb whereupon the friction and wear performance can be predicted based on physical and mechanical properties. Therefore, each developed formulation needs to be subjected to dynamometer test for screening purpose prior to on‐vehicle test to reduce development cost and. In this study, four formulations developed for passenger cars through powder metallurgy technique were subjected to dynamometer tests in accordance with Society of Automotive Engineers standard SAE 2552, dynamometer global brake effectiveness test. Test results show that sample S2 and S8 comply with the minimum requirement under all test segments and hence prototype sample could be prepared for further evaluation by performing on the road performance test.

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81.40.Pq	Friction, lubrication, and wear
07.10.Pz	Instruments for strain, force, and torque
81.20.Ev	Powder processing: powder metallurgy, compaction, sintering, mechanical alloying, and granulation
68.37.Hk	Scanning electron microscopy (SEM) (including EBIC)

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Microstructure Evolution During Rapid Debinding of MIM Compact

M. A. Omar and I. Subuki

AIP Conf. Proc. 1217, pp. 47-51; doi:http://dx.doi.org/10.1063/1.3377871 (5 pages)

Online Publication Date: 30 March 2010

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This paper discusses the microstructure changes during solvent solvent extraction and polymer burnout process of injection moulded component using a new developed palm stearin binder system. The samples were prepared by injection moulding mixture of stainless steel with palm stearin and polyethylene. Debinding was carried out in two steps; first, the moulded parts were immersed in heptane at a temperature of 40° C, 60° C and 80° C to remove the palm stearin (solvent extraction process) then followed by thermal debinding to remove the insoluble binder of polyethylene. The results show that large pore were formed from the surface to the interior of the debound part during solvent extraction, allowed easy escape of pyrolysis gases during thermal debinding. The rate of extraction of palm stearin from the green body increased with increasing solvent extraction temperature.

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81.40.Cd	Solid solution hardening, precipitation hardening, and dispersion hardening; aging
82.20.Yn	Solvent effects on reactivity
83.50.Uv	Material processing (extension, molding, etc.)
68.37.Hk	Scanning electron microscopy (SEM) (including EBIC)

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Comparison between Palm Oil Derivative and Commercial Thermo‐Plastic Binder System on the Properties of the Stainless Steel 316L Sintered Parts

R. Ibrahim, M. Azmirruddin, G. C. Wei, L. K. Fong, N. I. Abdullah, K. Omar, M. Muhamad, and S. Muhamad

AIP Conf. Proc. 1217, pp. 52-57; doi:http://dx.doi.org/10.1063/1.3377882 (6 pages)

Online Publication Date: 30 March 2010

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Binder system is one of the most important criteria for the powder injection molding (PIM) process. Failure in the selection of the binder system will affect on the final properties of the sintered parts. The objectives of this studied is to develop a novel binder system based on the local natural resources and environmental friendly binder system from palm oil derivative which is easily available and cheap in our country of Malaysia. The novel binder that has been developed will be replaced the commercial thermo‐plastic binder system or as an alternative binder system. The results show that the physical and mechanical properties of the final sintered parts fulfill the Metal Powder Industries Federation (MPIF) standard 35 for PIM parts. The biocompatibility test using cell osteosarcoma (MG63) and vero fibroblastic also shows that the cell was successfully growth on the sintered stainless steel 316L parts indicate that the novel binder was not toxic. Therefore, the novel binder system based on palm oil derivative that has been developed as a binder system fulfills the important criteria for the binder system in PIM process.

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83.50.Uv	Material processing (extension, molding, etc.)
81.40.Lm	Deformation, plasticity, and creep
07.20.Fw	Calorimeters
83.60.Fg	Shear rate dependent viscosity

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Optical and Structural Properties of a‐SiC:H prepared by Hot‐wire CVD Technique at Various Gas Flow

A. Azis and S. A. Rahman

AIP Conf. Proc. 1217, pp. 58-64; doi:http://dx.doi.org/10.1063/1.3377889 (7 pages)

Online Publication Date: 30 March 2010

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a‐SiC:H films were prepared using a home‐built hot‐wire chemical vapor deposition (HW‐CVD) system. Silane and methane gases were used as source gases and were allowed to flow into the chamber at different flow rate ratios. The a‐SiC:H films were deposited on preheated crystal silicon and glass substrates. FTIR spectra shows the existence of Si‐C stretching bond for all samples with its intensity is obviously higher for a‐SiC:H films prepared at higher methane to silane gas flow rate ratios. The increment of methane to silane gas flow rate ratio has enhanced the formation of Si‐C bonds and thus increasing the optical energy gap (E_g) consistently. High methane to silane gas flow rate ratio also resulted in rapid growth of a‐SiC:H films. Raman spectra show evidence of amorphous Si (a‐Si) structure in all samples. Study shows that the optical and structural properties of a‐SiC:H film was highly influenced by different gas flow rate ratio of the source gases.

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81.15.Gh	Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
47.80.Cb	Velocity measurements
71.20.Rv	Polymers and organic compounds
82.80.Dx	Analytical methods involving electronic spectroscopy
82.80.Gk	Analytical methods involving vibrational spectroscopy

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Microstructural Characterisation of Giant Magnetoresistive Co∕Cu Multilayers

K. Y. Kok and I. K. Ng

AIP Conf. Proc. 1217, pp. 65-71; doi:http://dx.doi.org/10.1063/1.3377890 (7 pages)

Online Publication Date: 30 March 2010

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Antiferromagnetically‐coupled Co∕Cu multilayers prepared by magnetron sputtering exhibit pronounced giant magnetoresistance (GMR) effect at room temperature. Using both diffraction and imaging techniques, we studied the in‐plane and out‐of‐plane crystallographic and layering microstructural features of these multilayers. Dominant characteristic features associated with the multilayers, such as the lateral and vertical columnar grain orientations as well as layer undulations and regularity, were identified. By deliberately introducing microstructural changes to the materials system using buffer layer and heat treatment, detailed microstructural analysis had provided an insight into the dependence of GMR on the microstructures of the multilayers.

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81.15.Cd	Deposition by sputtering
75.47.De	Giant magnetoresistance
75.70.Cn	Magnetic properties of interfaces (multilayers, superlattices, heterostructures)
75.50.Ee	Antiferromagnetics
68.37.Lp	Transmission electron microscopy (TEM)

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Corrosion Behaviour of Al Alloys in Sea Water

S. R. M. Kamarudin, M. Daud, A. Muhamad, M. S. Sattar, and A. R. Daud

AIP Conf. Proc. 1217, pp. 72-76; doi:http://dx.doi.org/10.1063/1.3377892 (5 pages)

Online Publication Date: 30 March 2010

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The electrochemical behaviour of aluminum (Al) alloys in seawater medium was investigated using potentiodynamic technique, complemented by Scanning Electron Microscopy (SEM) and EDAX. SEM was used to characterize the corroded surface and to observe the extent of corrosion attack on the Al alloys after tested in seawater. EDAX analysis was used to identify elements present on the specimen surface. The results indicate that influences of alloying elements present in the Al alloys play important role in the corrosion of Al alloys in seawater. The behaviour of Al alloys with addition of Zn, Sn, Cu and Si was greatly enhanced in terms of its potential and corrosion behaviour. Potential of Al with alloying elements reached value more negative than −0.9 V_SCE and showed active corrosion behaviour.

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81.05.Bx	Metals, semimetals, and alloys
68.37.Hk	Scanning electron microscopy (SEM) (including EBIC)
82.80.Fk	Electrochemical methods
71.20.Lp	Intermetallic compounds

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The Production and Characterization of Near Stoichiometric NdFeB‐Type HDDR Powder

A. Shaaban

AIP Conf. Proc. 1217, pp. 78-82; doi:http://dx.doi.org/10.1063/1.3377893 (5 pages)

Online Publication Date: 30 March 2010

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A study of the processing of HDDR powder with the composition Nd_12.7Fe_81.3B_6.0 and Nd_12.2Fe_81.2B_5.9Zr_0.1 have been undertaken. The homogenized alloys were disproportionated at 850° C for 30 minutes and employing a range of recombination temperatures from 790° C to 920° C. The optimum recombination temperature in the HDDR treatment was found to be 880° C. Zr‐addition appears to inhibit grain growth during the treatment process.

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81.05.Bx	Metals, semimetals, and alloys
81.20.Ev	Powder processing: powder metallurgy, compaction, sintering, mechanical alloying, and granulation
61.66.Bi	Elemental solids
61.66.Dk	Alloys
61.05.cp	X-ray diffraction

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Determination of Crystal Changes on Sodium Cobaltite (NaCo₂O₄) by Reitveld Analysis as a Suitability Function in Thermoelectric Materials

M. A. Idris, D. Murizam, and M. Norsuria

AIP Conf. Proc. 1217, pp. 83-88; doi:http://dx.doi.org/10.1063/1.3377894 (6 pages)

Online Publication Date: 30 March 2010

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Sodium Cobaltite, NaCo₂O₄ has been studied extensively as a new thermoelectric material. The cobalt oxide position in each sodium unit cell may determine the power produced by this type of thermoelectric materials. In this study, several set of samples were prepared by adding a fixed amount of cobalt oxide, Co₃O₄ into various quantity of sodium carbonate, [(1+x)Na₂CO₃ (where x = 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0)] which then sintered at 1000° C for 6 hours. The XRD results show the structure posed the P63∕mmc hexagonal structure. Rietveld analysis had been done to determine the crystal parameter. The parameters show that the crystal structure was changed with an addition of sodium carbonate, NaCo₂O₄ until a limit where the further addition of NaCo₂O₄ may cause destruction of the structure.

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72.15.Jf	Thermoelectric and thermomagnetic effects
61.05.cp	X-ray diffraction
72.20.Pa	Thermoelectric and thermomagnetic effects

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Chemical Properties of Carbon Nanotubes Prepared Using Camphoric Carbon by Thermal‐CVD

A. A. Azira and M. Rusop

AIP Conf. Proc. 1217, pp. 89-94; doi:http://dx.doi.org/10.1063/1.3377895 (6 pages)

Online Publication Date: 30 March 2010

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Chemical properties and surface study on the influence of starting carbon materials by using thermal chemical vapor deposition (Thermal‐CVD) to produced carbon nanotubes (CNTs) is investigated. The CNTs derived from camphor were synthesized as the precursor material due to low sublimation temperature. The major parameters are also evaluated in order to obtain high‐yield and high‐quality CNTs. The prepared CNTs are examined using field emission scanning electron microscopy (FESEM) to determine the microstructure of nanocarbons. The FESEM investigation of the CNTs formed on the support catalysts provides evidence that camphor is suitable as a precursor material for nanotubes formation. The chemical properties of the CNTs were conducted using FTIR spectroscopy and PXRD analysis. The high‐temperature graphitization process induced by the Thermal‐CVD enables the hydrocarbons to act as carbon sources and changes the aromatic species into the layered graphite structure of CNTs.

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81.15.Gh	Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
81.07.De	Nanotubes
68.37.Hk	Scanning electron microscopy (SEM) (including EBIC)
72.15.Cz	Electrical and thermal conduction in amorphous and liquid metals and alloys
61.72.Dd	Experimental determination of defects by diffraction and scattering

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Morphology Study of Prepared Carbon Nanotubes using Palm Oil as Carbon Source in Spray Pyrolysis Chemical Vapor Deposition

A. A. Azira and M. Rusop

AIP Conf. Proc. 1217, pp. 95-99; doi:http://dx.doi.org/10.1063/1.3377896 (5 pages)

Online Publication Date: 30 March 2010

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Surface morphology study on the influence of starting carbon materials by using newly developed spray pyrolysis chemical vapor deposition (Spray‐CVD) to produced carbon nanotubes (CNTs) is investigated. The CNTs derived from palm oil as carbon sources were synthesized in Argon gas ambient by using Spray‐CVD system. The major parameters are also evaluated in order to obtain high‐yield and high‐quality CNTs. The prepared CNTs are examined using field emission scanning electron microscopy (FESEM) and high resolution transmission electron microscope (HR‐TEM) to determine the microstructure of nanocarbons. The FESEM investigation of the CNTs formed on the support catalysts provides evidence that palm oil can serve as a precursor materials for nanotubes formation. The high‐temperature graphitization process induced by the Spray‐CVD enables the hydrocarbons to act as carbon sources and changes the aromatic species into the layered graphite structure of CNTs. The palm oil of hydrocarbons not only found acts as the precursors but also enhances the production rate of CNTs.

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81.15.Gh	Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
81.07.De	Nanotubes
68.37.Lp	Transmission electron microscopy (TEM)
81.05.-t	Specific materials: fabrication, treatment, testing, and analysis
82.30.Lp	Decomposition reactions (pyrolysis, dissociation, and fragmentation)

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Surface Study of Carbon Nanotubes Prepared by Thermal‐CVD of Camphor Precursor

A. A. Azira and M. Rusop

AIP Conf. Proc. 1217, pp. 100-105; doi:http://dx.doi.org/10.1063/1.3377792 (6 pages)

Online Publication Date: 30 March 2010

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Surface morphology study on the influence of starting carbon materials by using thermal chemical vapor deposition (Thermal‐CVD) to produced carbon nanotubes (CNTs) is investigated. The CNTs derived from camphor were synthesized as the precursor material due to low sublimation temperature, which indirectly maybe cost effective. The major parameters are also evaluated in order to obtain high‐yield and high‐quality CNTs. The prepared CNTs are examined using field emission scanning electron microscopy (FESEM) and high resolution transmission electron microscope (HR‐TEM) to determine the microstructure of nanocarbons. The FESEM investigation of the CNTs formed on the support catalysts provides evidence that camphor is suitable as a precursor material for nanotubes formation. The high‐temperature graphitization process induced by the Thermal‐CVD enables the hydrocarbons to act as carbon sources and changes the aromatic species into the layered graphite structure of CNTs. The camphoric hydrocarbons not only found acts as the precursors but also enhances the production rate and the quality of CNTs.

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81.07.De	Nanotubes
81.15.Gh	Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
68.37.Lp	Transmission electron microscopy (TEM)
81.05.-t	Specific materials: fabrication, treatment, testing, and analysis

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Preparation of LiNi_0.5Mn_1.5O₄ for Lithium Batteries Via Solid‐State Redox Method using Nitrate and Acetate Based Reactants

A. Mat, K. S. Sulaiman, M. A. Sulaiman, and M. F. Hasim

AIP Conf. Proc. 1217, pp. 106-112; doi:http://dx.doi.org/10.1063/1.3377793 (7 pages)

Online Publication Date: 30 March 2010

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LiNi_0.5Mn_1.5O₄ is a potential cathode material for 5 V batteries. This material was prepared by the solid‐state redox method using nitrate and acetate based reactants. The precursor material was obtained when the mixture reactants was heated at 500° C for 10 hours and calcined at different temperatures in the range between 650 and 950° C for 12 hours. The structures of the synthesized materials were verified with X‐ ray diffraction (XRD) measurement and Scanning Electron Microscope (SEM). The charge‐discharge technique was determined using Solartron 1470. As calcination temperature increases, the well‐ordered crystal growth oriented to [1 1 1] direction shows a clear octahedral morphology, which is the characteristic of the typical cubic spinel. The Li/LiNi_0.5Mn_1.5O₄ prepared from acetate based reactants calcined at 750° C for 12 h delivered the discharge capacity of 140 mAh∕g.

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82.47.Aa	Lithium-ion batteries
82.80.Fk	Electrochemical methods
87.64.Bx	Electron, neutron and x-ray diffraction and scattering
68.37.Hk	Scanning electron microscopy (SEM) (including EBIC)
82.30.Lp	Decomposition reactions (pyrolysis, dissociation, and fragmentation)

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Protective Agent‐Free Synthesis of Colloidal Cobalt Nanoparticles

M. D. L. Balela, Z. Lockman, A. Azizan, E. Matsubara, and A. V. Amorsolo, Jr.

AIP Conf. Proc. 1217, pp. 113-117; doi:http://dx.doi.org/10.1063/1.3377794 (5 pages)

Online Publication Date: 30 March 2010

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Spherical colloidal cobalt (Co) nanoparticles of about 2–7 nm were synthesized by hydrazine reduction in ethylene glycol at 80° C. The mean diameter of the Co nanoparticles was varied to some extent by changing the pH, temperature, Co(II) chloride hexahydrate concentration, and amount of hydrazine. The Co particle size was reduced by decreasing Co(II) chloride concentration and increasing amount of hydrazine.

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82.60.Qr	Thermodynamics of nanoparticles
82.70.Dd	Colloids
68.37.Lp	Transmission electron microscopy (TEM)
81.05.-t	Specific materials: fabrication, treatment, testing, and analysis
87.64.Bx	Electron, neutron and x-ray diffraction and scattering

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Synthesis of Nanostructured Carbides of Titanium and Vanadium from Metal Oxides and Ferroalloys Through High‐energy Mechanical Milling and Heat Treatment

P. Basu, P. F. Jian, K. Y. Seong, G. S. Seng, A. K. Masrom, Z. Hussain, and A. Aziz

AIP Conf. Proc. 1217, pp. 118-123; doi:http://dx.doi.org/10.1063/1.3377795 (6 pages)

Online Publication Date: 30 March 2010

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Carbides of Ti and V have been synthesized directly from their oxides and ferroalloys through mechanical milling and heat treatment. The powder mixtures are milled in a planetary ball mill from 15–80 hours and subsequently heat treated at 1000–1300° C for TiO₂‐C mixtures, at 500–550° C for V₂O₅‐C mixtures and at 600–1000° C for (Fe‐V)‐C mixtures. The milled and heat treated powders are characterized by SEM, EDAX, XRD, and BET techniques. Nanostructured TiC has been successfully synthesized under suitable processing conditions. However, carbides of vanadium is unidentified even though possibilities of V₂O₅‐C reaction are indicated with an extent of induced amorphism in the powder mixture. Density, specific surface area and particle size of the milled and heat treated mixtures are correlated with heat treatment temperatures. Similar attempts are also made to synthesize vanadium carbides from industrial grade Fe‐V.

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81.07.Bc	Nanocrystalline materials
81.05.Je	Ceramics and refractories (including borides, carbides, hydrides, nitrides, oxides, and silicides)
81.05.Bx	Metals, semimetals, and alloys
81.20.Wk	Machining, milling
68.37.Hk	Scanning electron microscopy (SEM) (including EBIC)
81.20.Ev	Powder processing: powder metallurgy, compaction, sintering, mechanical alloying, and granulation

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Studies on the Properties of Plasticizer and Lithium Salt on PMMA‐based Solid Polymer Electrolytes

K. W. Chew, C. G. Tan, and Z. Osman

AIP Conf. Proc. 1217, pp. 124-128; doi:http://dx.doi.org/10.1063/1.3377797 (5 pages)

Online Publication Date: 30 March 2010

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The effects of plasticizer and lithium salt on PMMA‐based solid polymer electrolyte have been investigated. In current project, three system samples consisted of pure poly(methyl methacrylate (PMMA) system, plasticized poly(methyl methacrylate) (PMMA‐EC) system and the LiCF₃SO₃ salted‐poly(methyl methacrylate) containing a fixed amount of plasticizer ([PMMA‐EC]‐LiCF₃SO₃) system have been prepared using solution casting technique. The conductivities of the films from each system are characterized by impedance spectroscopy and infrared spectrum. With the addition of plasticizer, results show improvement on the ionic conductivity value where the value of 6.25×10⁻¹⁰ Scm⁻¹ is obtained. This may be due to the nature of plasticizer that softens the polymer and hence enhanced the ionic transportation across the polymer. The room temperature conductivity for the highest conducting sample in the ([PMMA‐EC]‐ LiCF₃SO₃) system is 1.36×10⁻⁵ Scm⁻¹. Fourier Transform Infrared Spectroscopy (FTIR) indicates complexation between the polymer and the plasticizer and the polymer, the plasticizer and the salts, and the result of XRD further supports the observation.

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82.45.Gj	Electrolytes
82.35.Rs	Polyelectrolytes
81.40.Lm	Deformation, plasticity, and creep
82.80.Fk	Electrochemical methods
87.64.Bx	Electron, neutron and x-ray diffraction and scattering

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Formation of Nitrogen‐Pearlite in the Diffusion Bonding of Sialon to 316L Stainless Steel

P. Hussain, O. Mamat, M. Mohammad, and W. M. N. W. Jaafar

AIP Conf. Proc. 1217, pp. 129-133; doi:http://dx.doi.org/10.1063/1.3377798 (5 pages)

Online Publication Date: 30 March 2010

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The objective of this study is to investigate the interface reaction and diffusion bonding between 316L stainless steel and sialon. Bonding was carried out in a hot press at 1250° C under the pressure of 15 MN/m² for 1 hour and was cooled slowly in the furnace to prevent the mismatch between the sialon and the steel. Scanning Electron microscopy (SEM) revealed the interdiffusion and intereaction between the steel and the sialon. The elements diffusing into sialon were illustrated by the Energy Dispersive Spectrometer (EDS) analysis where the presence of Fe, Cr, Ni and Mn are significant. The formation of nitrogen pearlite can be described as a result of the reaction between the stainless steel and the silicon nitride component of sialon which release nitrogen. Mechanical behavior of the nitrogen diffused layer was also investigated using microhardness tester and at the reaction layer an increase in hardness was observed. Conclusion can be deduced that the formation of nitrogen pearlite in the stainless steel is quite significant especially on joining sialon to as‐received nitrogen‐free austenite stainless steel. The formation of nitrogen pearlite could be understood by the diffusion of nitrogen into the stainless steel. Thus, the continuous precipitates form lamellar nitrogen pearlite.

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68.35.Ct	Interface structure and roughness
68.37.Hk	Scanning electron microscopy (SEM) (including EBIC)
61.72.Ff	Direct observation of dislocations and other defects (etch pits, decoration, electron microscopy, x-ray topography, etc.)
81.20.Vj	Joining; welding

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Fabrication of Titania Nanotubes for Gas Sensing Applications

A. A. Dzilal, M. N. Muti, and O. D. John

AIP Conf. Proc. 1217, pp. 134-139; doi:http://dx.doi.org/10.1063/1.3377799 (6 pages)

Online Publication Date: 30 March 2010

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Detection of hydrogen is needed for industrial process control and medical applications where presence of hydrogen indicates different type of health problems. Titanium dioxide nanotube structure is chosen as an active component in the gas sensor because of its highly sensitive electrical resistance to hydrogen over a wide range of concentrations. The objective of the work is to fabricate good quality titania nanotubes suitable for hydrogen sensing applications. The fabrication method used is anodizing method. The anodizing parameters namely the voltage, time duration, concentration of hydrofluoric acid in water, separation between the electrodes and the ambient temperature are varied accordingly to find the optimum anodizing conditions for production of good quality titania nanotubes. The highly ordered porous titania nanotubes produced by this method are in tabular shape and have good uniformity and alignment over large areas. From the investigation done, certain set of anodizing parameters have been found to produce good quality titania nanotubes with diameter ranges from 47 nm to 94 nm.

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81.07.De	Nanotubes
82.30.Rs	Hydrogen bonding, hydrophilic effects
82.45.Cc	Anodic films
68.37.Hk	Scanning electron microscopy (SEM) (including EBIC)

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Properties of Amorphous Carbon Thin Films for Solar Cell Applications

F. Mohamad, N. M. Hanib, U. M. Noor, and M. Rusop

AIP Conf. Proc. 1217, pp. 140-146; doi:http://dx.doi.org/10.1063/1.3377800 (7 pages)

Online Publication Date: 30 March 2010

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This paper is presented the properties of amorphous carbon (a‐C) thin films for solar cell application. Amorphous carbon thin films have been deposited on silicon substrate by thermal chemical vapor deposition (thermal‐CVD) method at various deposition temperatures. The surface morphology, electrical properties and crystallinity of these films have been studied using Analytical Scanning Electron Microscope (SEM) JEOL JSM‐6360LA, Current Voltage (I‐V) Measurement (Advantest R6243 DC Voltage Current Source/Monitor Software) and the D5000 Siemen Difractrometer (XRD) respectively . It was found that increasing deposition temperature had the most influence on the a‐C thin films properties. In addition the carrier gas flow also showed a secondary impact on the properties of a‐C thin films.

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81.15.Gh	Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
72.15.Cz	Electrical and thermal conduction in amorphous and liquid metals and alloys
68.37.Hk	Scanning electron microscopy (SEM) (including EBIC)
81.15.Aa	Theory and models of film growth

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