Xains Info: October 2008

The Electronic Structure ofWurtzite MnS

Manganese sulfide thin films have been investigated by X-ray Absorption Fine Structure spectroscopy(XAFS). XAFS provides a description of the structure of the films. The paper also presents a structural characterisationof the wurtzite MnS thin films and their crystallisation behaviour by annealing at increasing temperatures. The x-rayabsorption fine structure (XAFS) ofMn K-edge and S K-edge in wurtzite MnS have been investigated. The full multiplescattering approach has been applied to the calculation of Mn Kedge XANES spectra of MnS. The calculations arebased on different choices of one electron potentials according to Mn coordinations by using the real space multiplescattering method FEFF 8.0 code. The crystallographic and electronic structure of the MnS are tested at varioustemperature ranges from 300 to 573 K. We have found prominent changes in the XANES spectra of Mangeanese sulfidethin films by the change of the temperature. Such observed changes are explained by considering the structural,electronic and spectroscopic properties. The results are consistent with experimental spectra.Keywords: MnS Thin Film, Electronic Properties, Chalcogenide, XANESO. Murat Ozkendir, A. Turker Tuzemen, Y. UfuktepePhysics Department, University ofCukurova, OJ330 Adana, Turkey

TWO-DIMENSIONAL HYDRODYNAMICS COMPUTER SIMULATION ON THE FORMATION OF TERRESTRIAL COMET TAIL DUE TO SOLAR WIND BLOWS

Hydrodynamics pressure due to relative motion of the terrestrial comet whenapproaching the Sun is simulated in two-dimensional space. The ambient solar windintroduced relative momentum on the comet materials. The material evaporates andleft behind the comet-head as a tail. Direction of the tail-vector always opposes to the-directionof motion if it is still far enough from the Sun. Before a tail is formed, it isobvious from our simulations that outer-most soft material will firstly dismantle andevaporate. The soft material is blown away and the tail is formed subsequently.Keywords: Solar wind, hydrodynamic simulations, comet tail formation. Bambang SetiahadiIndonesian National Institute of Aeronautics and Space (LAPAN)Watukosek, Gempol,P.O.Box04,Pasuruan67155,EastJavaPhone:0343851887,Fax:0343852311,HP:085648626737e-mail: bsetiapx14@yahoo.co.id

Synthesis and Characterization of Double Perovskite Sr2Mgl-xMnxMo06 as Anode Materials in Fuel Cell

The anode materials in the solid oxide fuel cell (SOFC) require properties such as high electric conductivity,high catalytic effect for hydrogen decomposition from hydrocarbon and good resistant to sulfur. For these purposes,anode materials based on double perovskite structure, AzBB'06, were synthesized and studied. In this work, doubleperovskite compounds, SrzMgl_xMnxMo06_0 (SMMMO) with 0 ~ x ~ I, were synthesized by means of solid statereaction technique at 1350 °C. Crystal structures were determined using X-rays diffractometer and analyzed with theRIETICA program, by employing Le Bail method. The oxides materials showed to adopt monoclinic structure withspace group of P211n. For SMMO with higher x, the lattice parameters and the unit-cell volume become smaller. SEM(Scanning Microscope Electron) image, which gave the morphology of SMMMO showed that grains size was increasedwith the increasing ofx. Meanwhile, the DC measurement for electrical conductivity as function of temperature revealedthat the conductivity increases with the increasing ofx.Keywords: SMMO,double perovskite, SOFC, X-ray diffractionPACS: 61.l0.Nz, 61.43.Gt, 66.1O.Ed. N. R. Sari, Ismunandar and B. PrijamboediInorganic and Physical Chemistry Research Division,Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesha 10, Bandung, INDONESIA

Synthesis and Characterization of Double Perovskite Sr2Mgl-xMnxMo06 as Anode Materials in Fuel Cell

The anode materials in the solid oxide fuel cell (SOFC) require properties such as high electric conductivity,high catalytic effect for hydrogen decomposition from hydrocarbon and good resistant to sulfur. For these purposes,anode materials based on double perovskite structure, AzBB'06, were synthesized and studied. In this work, doubleperovskite compounds, SrzMgl_xMnxMo06_0 (SMMMO) with 0 ~ x ~ I, were synthesized by means of solid statereaction technique at 1350 °C. Crystal structures were determined using X-rays diffractometer and analyzed with theRIETICA program, by employing Le Bail method. The oxides materials showed to adopt monoclinic structure withspace group of P211n. For SMMO with higher x, the lattice parameters and the unit-cell volume become smaller. SEM(Scanning Microscope Electron) image, which gave the morphology of SMMMO showed that grains size was increasedwith the increasing ofx. Meanwhile, the DC measurement for electrical conductivity as function of temperature revealedthat the conductivity increases with the increasing ofx.Keywords: SMMO,double perovskite, SOFC, X-ray diffractionPACS: 61.l0.Nz, 61.43.Gt, 66.1O.Ed. N. R. Sari, Ismunandar and B. PrijamboediInorganic and Physical Chemistry Research Division,Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesha 10, Bandung, INDONESIA

Powder Diffraction Studies of Phase Transitions in Manganese Perovskites

The results of recent structural studies of some Manganese perovskites are presented, in particular oxides inthe system Cal_xSrxMn03 and SrRllo.sMno.503' In the fIrst series we fIrstly show the power of synchrotron X-ray powderdiffraction to refme accurate and precise structures for oxides containing fIrst row transition metals and then show thepresence of a direct orthorhombic Pbnm to tetragonal 14/mcm transition associated with the tilting of the Mn06octahedra. The inclusion of a heavier second row transition metal reduces the precision of the structure, however thedetails of the tetmgonal to cubic phase transition in SrRllo.sMno.503 are still established.Keywords: Perovskite, Phase Transition, Synchrotron X-ray Powder Diffraction, Jahn- Teller DistortionB. J. Kennedy; School of Chemistry, The University of Sydney, Sydney, NSW 2006 Australia

Application of X-ray and Neutron Scattering Techniques in Materials Research: Lithium Batteries and Electronic

X-ray and neutron powder diffraction provide complementary information on the structures of inorganiccomplex oxides, primarily because of the different dependence of atomic scattering power, or scattering length, onatomic number. Neutron diffraction is particularly useful for characterising novel lithium transition metal oxides whichhave applications in prototype advanced lithium battery systems. Thus, it is possible to establish conduction pathwaysfor mobile Li+ ions and to distinguish between transition metal ions in ordered spinel structures such as Li2NiMn30s,which has a charge-discharge potential of 4.7V. An additional feature of such materials is oxygen non-stoichiometry inwhich their oxygen content depends on sample preparation conditions and temperature. This oxygen non-stoichiometrymay be analysed by thermogravimetry and the transition metal oxidation states determined, in the solid state, by the X-rayabsorption technique, XANES. Structural changes as a function of temperature may be followed by high temperaturediffraction methods and as a function of lithium content during charging/discharging of lithium batteries by in situsynchrotron XRD. A range of examples of the applications of these techniques will be presented.A. R. WestUniversity of Sheffield, Department of Engineering Materials,Sir Robert Hadfield Building, Mappin Street, Sheffield, SJ 3JD, United Kingdom

Synthesis and X-ray Structural Study on the Complexes of Silver(I) Halide with Tricyclohexylephosphine, Diphenyl-(2,4,6- trimethoxy)phenylphosphine

A diverse array of structures for the complexes of silver(I) halide with triphenylphosphine (PPh3) has beenstudied. The complexes may be described as being of the type [AgX(PPh3)n] (X = Cl, Br or I). The value of n varies inthe range of 1-3. This also indicates that the stoichiometry of the complexes is in the range of 1-3. The complex withstoichiometry 1:1 is a tetramer. There are two structural types of tetramer reported, termed cubane and step or chair. Thecubane structure has been reported for [AgX(pPh3)]4ex = Cl, Br or I), while the step structure has only been reported for[AgI(PPh3)]4' The complex with stoichiometry 1:2 may be a monomer or a dimer. The monomer has a quasi trigonalplanar structural type and has only been reported for [AgBr(PPh3)2l The dimer has been reported for [(PPh3)2Ag(J.!-X)2Ag(PPh3)2](X = Cl or Br) with silver atom in the distorted tetrahedral environment. The complex with stoichiometry1:3 has a distorted tetrahedral structural type and has been reported for [AgX(PPh3)3](X = Cl, Br or I). Changing PPh3with more hindered ligand such as tricyclohexylephosphine (PCY3)or derivative of PPh3 such as diphenyl-2,4,6-trimethoxy(phenyl)phosphine (dpmp), phenyl-bis{2,4,6-trimethoxy(phenyl)} phosphine (pdmp), or tris{2,4,6-trimethoxy(phenyl)}phosphine (tmpp) may give complexes with various structural types but with lower range ofstoichiometry. Synthesis and X-ray structural study of these complexes has been done with the results summarizedbelow. Silver(I) halide and PCY3give complexes with stoichiometry 1:1 and 1:2. The complex with stoichiometry 1:1 isa dimer or cubane. The dimer is observed for [(PcY3)Ag(J.!-X)2Ag(PCY3)] ex = Cl or Br). The unusual dimer is observedfor [(PcY3)Ag(J.!-IMJ.!-py)Ag(PCY3)] where the pyridine ligand is bonded to two silver atoms. The cubane is observed for[AgI(PCY3)J4,The complex with stoichiometry 1:2 has a quasi trigonal planar structural type and has been observed for[AgX(PCY3)2]ex = Cl, Br, I). Silver(I) halide and dpmp give complexes with stoichiometry 1:1 and 1:2. The complexwith stoichiometry 1:1 is a dimer and has been observed for [(dpmp)Ag(J.!-X)2Ag(dpmp)]ex = Cl, Br or I). The complexwith stoichiometry 1:2 has a quasi trigonal planar structural type and has been observed for [AgX(dpmp)2] (X = Cl, Br,I). Silver(I) halide and pdmp also give complexes with stoichiometry 1:1 and 1:2. The complex with stoichiometry 1:1 isa dimer and has been observed for [(pdmp)Ag(J.!-X)2Ag(pdmp)](X = CI, Br or I). The complex with stoichiometry 1:2has a quasi trigonal planar structural type and has been observed for [AgX(pdmp)2] (X = CI, Br, I). Silver(I) halide andtmmp only give complexes with stoichiometry I: I. This complex is a monomer and has been observed for [AgX(tmpp)](X = Cl or Br). In this complex the silver atom is in a quasi linear environment. Based on the bond lengths betweensilver and phosphorous atoms in the complexes obtained, it can be concluded that bulky ligands tend to give complexeswith lower range of stoichiometry. In addition, the bulkier the ligand the longer the bond length between the silver andphosphorous atoms. Effendy1 and A. H. White2/Jurusan Kimia, FMIPA Universitas Negeri Malang, Jl. Surabaya 6Malang 65145, Indonesia2 Chemistry, School of Biomedical, Biomolecular, and Chemical Sciences, The University of WesternAustralia, 35 Stirling Highway, Crawley WA 6009, Australia

Heterostructure Thin Films Grown on Si(111) Substrate by Plasma Assisted Metalorganic Chemical Vapor Deposition

Microstructure and optical properties of AlxGal_xN/GaN heterostructures thin films grown on Si(111)substrate by Plasma Assisted-Metalorganic Chemical Vapor Deposition (PA-MOCVD) were investigated. The surfacemorphology and crystal orientation of the films were determined by scanning electron microscope (SEM) and X-raydiffractometer (XRD), respectively. The content of Al in AlxGal_xNfilms (x) was determined by means of NIR-UVvisible optical reflectance spectroscope. The surface morphology of films depends significantly on the content of AI.Films with higher value of x showed the smaller grain size and the smoother surface. Films with x = 0.29 and x = 0.36showed crystal orientation of (1010) plane, while films with x = 0.12 have two crystal orientation of (1010) and (1011)planes. The optical reflectance spectra showed that the ordered of oscillation depend on the smoothness of the filmsurface, while the number of oscillation related to the thickness of films. The calculated band gap was 3.34 eV for GaNand in the range of 3.34 to 6.20 eV for AlxGal_xNdepending on the x values.Keywords: AlxGal_xN/GaN,MOCVD, crystal structure, optical reflectance.PACS: 78.55.Cr, 78.66.Fd. H. Sutantol,2, A. Subagiol,2, E. Supriyanto1,3, P. Arifinl,M. Budimanl, Sukimol, M. BarmawilJ Laboratory of Electronic Material Physics, Bandung Institute ofTecll1lology, BandungJI. Ganesha No. 10 Bandung 40132, Indonesia2Department of Physics, Diponegoro University, SemarangKampus MIPA-UNDIP, Jl. Prof. Soedharto, SR, Tembalang-Semarang 50275, Indonesia3Department of Physics, Jember University, JemberJI. Kalimantan 1Il/25Kampus Tegalboto-Jember, Indonesia

Heterostructure Thin Films Grown on Si(111) Substrate by Plasma Assisted Metalorganic Chemical Vapor Deposition

Microstructure and optical properties of AlxGal_xN/GaN heterostructures thin films grown on Si(111)substrate by Plasma Assisted-Metalorganic Chemical Vapor Deposition (PA-MOCVD) were investigated. The surfacemorphology and crystal orientation of the films were determined by scanning electron microscope (SEM) and X-raydiffractometer (XRD), respectively. The content of Al in AlxGal_xNfilms (x) was determined by means of NIR-UVvisible optical reflectance spectroscope. The surface morphology of films depends significantly on the content of AI.Films with higher value of x showed the smaller grain size and the smoother surface. Films with x = 0.29 and x = 0.36showed crystal orientation of (1010) plane, while films with x = 0.12 have two crystal orientation of (1010) and (1011)planes. The optical reflectance spectra showed that the ordered of oscillation depend on the smoothness of the filmsurface, while the number of oscillation related to the thickness of films. The calculated band gap was 3.34 eV for GaNand in the range of 3.34 to 6.20 eV for AlxGal_xNdepending on the x values.Keywords: AlxGal_xN/GaN,MOCVD, crystal structure, optical reflectance.PACS: 78.55.Cr, 78.66.Fd. H. Sutantol,2, A. Subagiol,2, E. Supriyanto1,3, P. Arifinl,M. Budimanl, Sukimol, M. BarmawilJ Laboratory of Electronic Material Physics, Bandung Institute ofTecll1lology, BandungJI. Ganesha No. 10 Bandung 40132, Indonesia2Department of Physics, Diponegoro University, SemarangKampus MIPA-UNDIP, Jl. Prof. Soedharto, SR, Tembalang-Semarang 50275, Indonesia3Department of Physics, Jember University, JemberJI. Kalimantan 1Il/25Kampus Tegalboto-Jember, Indonesia

Residual Stress Measurement of Titanium Casting Alloy by Neutron Diffraction

Neutron stress measurement can detect strain and stress information in deep region because of largepenetration ability of neutron beams. The present paper describes procedure and results in the residual stressmeasurement of titanium casting alloy by neutron diffraction. In this study, the three axial method using Hooke'sequation was employed for neutron stress measurement. This method was applied to the cylindrical shape sample oftitanium casting alloy (Ti-6AI-4V). Form the results of this study, this sample has large crystal grain in the inside wholeposition, it is assumed this large grain was grown up during casting manufacture process. Furthermore, the peak profileused to the stress measurement appears in very weak because of the HCP crystal system of titanium character and effectof large crystal grain. These conditions usually make difficult to measure the accuracy values of residual stresses.Therefore, it had to spend a long time to measure the satisfied data from titanium sample. Regarding to the results ofstress measurement, the stress values in the cylindrical sample of three directions is almost same tendency, and residualstresses change from the compressive state in the outer part to the tensile state in the inner part gradually.Keywords: Titanium, Residual stress, Neutron diffraction, Nondestructive estimation. M. Nishidal,*, T. Jing2, M. R. Muslih3 and T. Hanabusa4JDepartment of Mechanical Engineering, Kobe City College of Technology, Kobe, Japan2School of Materials Science and Engineering, Harbin institute of Technology, Harbin, China3Neutron Scattering Laboratory, BATAN, Kawasan Puspiptek Serpong , Indonesia4Dept. of Mechanical Engineering, Institute of Technology and Science, Tokushima University , Tokushima, Japan

SANS and SAXS Study of Block and Graft Copolymers Containing Natural and Synthetic Rubbers

Small-angle neutron scattering (SANS) and small-angle X-ray scattering (SAXS) are excellent techniques tostudy nano-scale concentration fluctuations in the two-component polymer systems such as block and graft copolymersand polymer blends. The miscibility, phase transitions, microphase-separated structures and interface thicknesses wereinvestigated by SANS and SAXS for the block and graft copolymers, which at least contain natural or synthetic rubberas one component.H. Hasegawa Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan

Monochromatic Neutron Tomography Using I-D PSD Detector at Low Flux Research Reactor

This paper describes the monochromatic neutron tomography experiment using the 1-D Position SensitiveNeutron Detector (PSD) located at Nuclear Malaysia TRIGA MARK II Research reactor. Experimental work wasperfonned using monochromatic neutron source from beryllium filter and HOPG crystal monochromator. The principalmain aim of this experiment was to test the detector efficiency, image reconstruction algorithm and the usage of 0.5 nmmonochromatic neutrons for the neutron tomography setup. Other objective includes gathering important parameters andfeatures to characterize the system.Keywords: monochromatic neutron, neutron tomography, Position Sensitive Neutron DetectorPACS: 81.70.Tx, 41.85.Si, 06.70.Dn. N. Abidin Asharil, J. Mohamad SalehI, M. Zaid Abdullahl,A. Aziz Mohamed2, A. Azman2, R. Jamro2I School of Electrical and Electronic Engineering, Universiti Sains Malaysia, Engineering Campus,14300 Nibong Tebal, Pulau Pinang, Malaysia2Malaysian Nuclear Agency (Nuclear Malaysia), 43000 Bangi, Selangor, Malaysia

X-Ray Powder Diffraction (XRD) Studies on Kenaf Dust Filled Chitosan Bio-composites

Kenaf dust filled chitosan bio-composites with various compositions of kenaf dust (i.e. 7%, 14%, 21 % and28%) were prepared using solution casting technique. The degree of relative crystallinity of the bio-composites wasdetermined using XRD method. Two distinguishable crystalline peaks were observed in the 28 range of 5 to 40° whichindexed as 020 and 110 respectively. It was noted that the maximum peak of intensity at 020 crystalline peak increasedwith addition of kenaf dust as well as the second maximum peak of intensity at 110. Consequently, Fourier TransformInfrared (FTIR) analysis was done to investigate the interaction between kenaf dust and chitosan matrix. From FTIRanalysis, corresponding peak of chitosan was detected at wavelength of 3233.2cm-1 indicated that there existintermolecular interactions between kenaf dust and chitosan matrix. These results highlighted that there are greaterintermolecular forces formed in chitosan with addition of kenaf dust. Intermolecular forces were attributed to theformation of inter and intra hydrogen bonding between chitosan polymer and cellulosic kenaf dust filler.Keywords: Chitosan, X-ray diffraction, FTIR. N. Muhd Julkapli and H. Md AkilSchool of Materials and Mineral Resources Engineering, Engineering Campus, Universiti Sains Malaysia,14300 Nibong Tebal, Pulau Pinang, Malaysia

Degradation of Aluminide Coatings in Fe-AI-Cr Alloy on the Isothermal Oxidation

Fe base superalloy has a good mechanical strength to be used as component operating at high temperaturewith oxidative environment. Although, the oxidation rate can not be tolerated as it will be oxidized and form oxide scaleof un-protective FeD. Coating is a proper solution that this alloy can be used at high temperature. In this research, packaluminizing on sample was conducted with temperatures of 900°C, 1000°C and I 100°C for 10 hours in inert (argon)environment and then an oxidation test was carried out at temperature of 650°C by an isothermal method for 10 hours inair environment. It was carried out an analysis for characteristics of coating and oxide scale formed in Fe-AI-Cr superalloy resulted from pack aluminizing. From this experiment, it was indicated by XRD analysis that the coating formedon substrate was a layer of FeAlz compound, other than coating it was found a diffused zone, where in this area itoccurred movement of Fe and Cr atoms from substrate toward coating, while Al atoms moved from coating to substrate.The increase of temperature of pack aluminizing process will affect settling rate of Al and coating growth.Keywords: Superalloy, pack aluminizing, isothermal oxidation.L. Juwital, D. H. Prajitno2, J. W. Soedarsono3, A. Manat1Materials Science Department, Indonesia University, JI. Salemba Raya 4, Jakarta /043, Indonesia.2Metallurgy Laboratory, PTNBR-BATAN, JI.Taman Sari 71, Bandung, Indonesia3Metallurgy Engineering Department, Indonesia University, Kampus UI Depok, Jawa Barat 16424, Indonesia4Materials Science Department, Indonesia University, JI. Salemba Raya 4, Jakarta 10430, Indonesia

Residual Stress Estimation of Ti Casting Alloy by X-ray Single Crystal Measurement Method

Recently, titanium casting teclmology attracts attention in tile industrial fields. These casting metals areincluding a various residual stresses due to the heat shrinkage and inclusion particles, et a!. In order to apply the castingteclmology, the accurate estimation of residual stresses is desired in many cases. In iliis study, it aims at thenondestructive stress evaluation of titanium casting material by the X-ray stress measurement teclmique. At first in thisstudy, the sin21Jf method which used in the usual X-ray stress measurement was tried to measure the residual stresses.However, it was unsuitable for measurement of titanium casting material because of including coarse grains. Therefore,another X-ray method for single crystal system was employed to coarse crystal grains, in order to investigate thepossibilities of residual stress estimating. Four-axes sample table which can set tile both of tilt angle and rotate one onthe sample surface was prepared. The stereographic diagrams and the theory of elasticity were used to measure tl1esingle crystal stresses on the sample surface.Keywords: Titanium (Ti), X-ray, residual stress measurement, casting alloy. A. Shirol, M. Nishida2, T. ling3; IAdvanced Course of Mechanical System engineering, Kobe City College of Technology, Kobe 651-2194, Japan2Department of Mechanical engineering, Kobe City College of Technology, Kobe 651-2194, Japan3School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China

Texture and Structure Analysis of AluminumA-I050 using Neutron Diffraction Technique

Analysis of bulk aluminum A-l050 has been performed using FCDrrD- BAT AN. From neutron diffractionpattern of bulk sample, two Bragg peaks, (220) and (200) are observed while three Bragg peaks of (Ill), (311) and(222) are over dumped. Due to preferred orientation, crystallites are highly oriented to <110> direction. Texture analysisfor pole figure reconstruction is performed for (200) and (220). From analysis result using MAUD program, a goodnessof fitting (0"= 1.259), crystallographic weighted error (Rw= 32.81 %) and texture error (Rp= 19.03 %) are obtained.Analysis of powder type of A-1050 is also carried out. From neutron diffraction measurement, Bragg peaks of (111),(200), (220), (311) and (222) are observed with highest intensity at (111). From analysis result 0" = 1.008, and Rw =16.68 % are obtained.Keywords: Pole figure, texture, Rietveld texture analysis (RT A), E-WIMVT. H. Priyanto, N. Suparno, Setiawan, M. R. MuslihNeutron Scattering Laboratory, Center of Technology for Nuclear Industrial MaterialsNational Nuclear Energy Agency of Indonesia - BATAN, Kawasan Puspiptek Serpong, Tangerang 153/4, Indonesia

The Effect of Sintering Soaking Time on Microstructural and Properties of CaCu3Mn4012System

The synthesis of CaCu~n4012 (CCMO) has been accomplished via solid-state reaction. The mixture wascalcined at 850 DC for 12 hours. Temperature of 1090 °c has been chosen with 6 differ soaking time ranging from 1 hourto 24 hours. The CCMO formation was confirmed using X-ray diffraction (XRD). The microstructure analysis wascarried out using field emission scanning electron microscopy (FESEM), while electrical properties have been studiedusing AutoLab POSTAT 30 Frequency Analyser. Results shows that differ soaking time for sintering introduce uniqueproperties for CCMO. Microstructural analysis reveal that soaking time more than 12 hours produce grains with almostuniform shape. The physical densification of the sintered pellets promotes the creation of new conduction channels andincrease of intergrain effective area for transport current under conductivity properties. Results for bulk conductivityvary from 0.2148 x 10-4to 0.5825 X 10-4Stcm.Keywords: CaCu3Mil4012'solid-state reaction, bulk conductivity. A.R. Mohd Warikh1, A.Z. Ahmad Zahirani2, S.D. Hutagalung2, A. Zainal Ahmad2IDepartment of Engineering Material, Faculty of Manufacturing Engineering,Universiti Teknikal Malaysia Melaka, Locked Backed 1200, Ayer Keroh, 75450 Melak, Malaysia.2 School of Materials and Mineral Resources Engineering, Engineering Campus,University Sains Malaysia, 14300 Nibong Tebal, Penang, Malaysia

Powder Diffraction Studies of Phase Transitions in Manganese Perovskites

The results of recent structural studies of some Manganese perovskites are presented, in particular oxides inthe system Cal_xSrxMn03 and SrRllo.sMno.503' In the fIrst series we fIrstly show the power of synchrotron X-ray powderdiffraction to refme accurate and precise structures for oxides containing fIrst row transition metals and then show thepresence of a direct orthorhombic Pbnm to tetragonal 14/mcm transition associated with the tilting of the Mn06octahedra. The inclusion of a heavier second row transition metal reduces the precision of the structure, however thedetails of the tetmgonal to cubic phase transition in SrRllo.sMno.503 are still established.Keywords: Perovskite, Phase Transition, Synchrotron X-ray Powder Diffraction, Jahn- Teller Distortion. B. J. KennedySchool of Chemistry, The University of Sydney, Sydney, NSW 2006 Australia

The trend of using laptop in students, especially in FKM VI is increase. Price of a laptop is

High intensity of using laptop in students is riskyand can occur of health effect. Therefor, this study was conducted to know the healthproblem in students who using laptop. This study uses cross-sectional design. Samples arestudents using laptop in campus, the number is 100 with simple random samplingtechnique. Data were collected by questionnaires, interview, and observation. The resultsshow that 97% felt of health effect. The parts of body that have health effect (pain) are neck,eye, shoulder, up of back, and carpal. Only a few of samples have pain in foot. 91.8% ofsamples who felt health effect have high risk condition when using laptop. Suggestion forstudents is using laptop with follow the it's function and ergonomics procedures and forlaptop manufacturers is complete their products with safety and ergonomic guidance forusing laptop.Keywords: laptop, health, ergonomics. Hendra, Devie Fitri OctavianiDepartemen K-3, Fakultas Kesehatan Masyarakat Universitas Indonesia

Oxidation of Ni and Ni-5% W

Oxidation of cube textured (100) <001> Ni and Ni-5%W foils were studied in order to verify ifNiO surfacelayer could be fonned on Ni-W similar to that Ni. The principle aim of this study is to prescribe the basic conditions forgrowing a compact, adherent, smooth, and cube texture NiO suitable to be used as a buffer layer in coated conductor,high temperature superconductor architecture. It was found that for Ni 30Jlm thick (002) NiO were fonned at oxidationtemperature of 1250 ± lOoe in air for 60 min. Under the same oxidation condition, (002) NiO with duplex-typemorphology was fonned on Ni-5%W which reduces the mechanical integrity of the sample. Furthennore, due to oxygendiffusion during the oxidation process, spherical NiW04 fonned inside the Ni-W substrate.Keywords: Oxidation, nickel, nickel oxide, nickel-tungsten, rolling assisted biaxially textured substrateZ. Lockman\ M. H. Jamaluddin\ R. Nast2I School of Materials and Mineral Resources Engineering, Universiti Sains Malaysia,14300 Nibong Tebal,Penang, Malaysia,2Forschungszentrum Karlsruhe, Institut fur Technische Physik, Karlsruhe, Germany

Characterization of a Water-based Surfactant Stabilized Ferrofluid by Different Scattering Techniques

Different scattering techniques dynamic light scattering (DLS), small-angle X-ray scattering (SAXS) and small-angle neutron scattering (SANS) have been used to characterize a water-based surfactant stabilized ferrofluid having ferrite (F~04) particles coated with oleic acid. DLS gives the overall size of the particle along with the thickness of the surfactant (oleic acid) coating and water of hydration attached to the particle. SAXS only measures the size of the ferrite particle due to poor contrast of surfactant coating for X-rays. SANS with the possibility to vary the contrast provides both the size of the ferrite particle and the thickness of the surfactant coating on the particle. Keywords: Ferrofluid, dynamic light scattering, small-angle scattering. V.K. Aswall, s. N. Chodankarl, P.U. Sastryl, P.A. Hassan2 and R.V. Upadhyal 1Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085, India 2Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085, India 3Department of Physics, Bhavnagar University, Bhavnagar 364 002, India

Structure and Function of Glucansucrases

Glucansucrases are relatively large (-160 kDa) extracellular enzymes produced by lactic acid bacteria. Using sucrose as a substrate they synthesize high molecular mass glucose polymers, called a-glucans, which allow the bacteria to adhere to surfaces and create a biofilm. The glucan polymers are of importance for the food and dairy industry as thickening and jellying agents. An overview is given of the current insights into the structure and functioning of these and related enzymes Keywords: glucansucrase; amylosucrase; crystal structure; catalysis; catalytic mechanism. B. W. Dijkstra and A. VujiCi6-Zagar; Laboratory of Biophysical Chemistry, University ofGroningen Nijenborgh 4,9747 AG Groningen, The Netherlands

The Influence of Base Concentration on the Surface Particle of Lithium Aluminosilicate System

The study of base concentration effect toward surface particles of lithium aluminosilicate glass ceramic system has been done by using NaOH solution. The parent glass with composition of 60% Si02, 31% Li20, 6% Al203 and 3% Ti02 in wtOlowas prepared by melting process at 1250 °C prior to quenching rapidly to room temperature. Sintering and crystallization process on this parent glass were carefully examined by Differential thermal analysis (DTA) and X-Ray Diffraction (XRD). Based on these analyses, the selected crystal has been chosen as a precursor material. There are two controlling parameter involved in this study i.e. NaOH concentration and leaching period. The morphology of the glass ceramic particle was observed by Field Emission Scanning Electron Microscope (FESEM). The result shows that by increasing the basic concentration as well as increasing the soaking leaching period, the tendency of glass ceramic particle to leach out is relatively high. Keywords: Lithium aluminosilicate, glass ceramic, leaching, porous PACS: 81.05.Kf. 1. M. Nazri, M. A. Sri Asliza and R. Othman School of Material and Mineral Resources Engineering, Engineering Campus Universiti Sains Malaysia, 14300 Nibong Tebal Pulau Pinang,Malaysia

The Effect of Sintering Soaking Time on Microstructural and Properties of CaCu3Mn4012System

The synthesis of CaCu~n4012 (CCMO) has been accomplished via solid-state reaction. The mixture was calcined at 850 DC for 12 hours. Temperature of 1090 °c has been chosen with 6 differ soaking time ranging from 1 hour to 24 hours. The CCMO formation was confirmed using X-ray diffraction (XRD). The microstructure analysis was carried out using field emission scanning electron microscopy (FESEM), while electrical properties have been studied using AutoLab POSTAT 30 Frequency Analyser. Results shows that differ soaking time for sintering introduce unique properties for CCMO. Microstructural analysis reveal that soaking time more than 12 hours produce grains with almost uniform shape. The physical densification of the sintered pellets promotes the creation of new conduction channels and increase of intergrain effective area for transport current under conductivity properties. Results for bulk conductivity vary from 0.2148 x 10-4to 0.5825 X 10-4Stcm. Keywords: CaCu3Mil4012'solid-state reaction, bulk conductivity. A.R. Mohd Warikh1, A.Z. Ahmad Zahirani2, S.D. Hutagalung2, A. Zainal Ahmad2 IDepartment of Engineering Material, Faculty of Manufacturing Engineering, Universiti Teknikal Malaysia Melaka, Locked Backed 1200, Ayer Keroh, 75450 Melak, Malaysia. 2 School of Materials and Mineral Resources Engineering, Engineering Campus,University Sains Malaysia, 14300 Nibong Tebal, Penang, Malaysia

Implementasi teknologi informasi di Perpustakaan

Siapakah kita? Dalam rangka menghadapi ledakan informasi, perpustakaan sebagai wadah pengelola sumber informasi harus dapat menghadapi dengan sigap. Perpustakaan harus dapat memenuhi segala kebutuhan informasi masyarakat/pengguna perpustakaan dengan cepat, tepat dan mudah. Maka terlepas siap atau tidak siap, perpustakaan harus dapat menerima kehadiran serta pengembangan sistem teknologi informasi, baik dalam bentuk otomasi perpustakaan maupun digitalisasi koleksi perpustakaan. Implementasi dan pengembangan teknologi informasi dalam suatu organisasi/lembaga mempunyai dampak yang sangat berarti, baik bagi sistem yang belaku maupun sumber daya manusia yang ada. Sumber daya manusia merupakan faktor utama sebagai pendukung dari pada implementasi sistem ini. Dampak yang diakibatkan oleh pengembangan sistem teknologi informasi bagi sumber daya manusia bukan merupakan halangan. Sikap antisipatif/dengan cara memotivasi kerja staf merupakan salah satu langkah yang dapat dilakukan dan kembangkan, yaitu dengan cara merubah pradigma, pelatihan secara intensif dan melibatkan secara langsung dalam penerapan dan pengembangannya. Perpustakaan merupakan lembaga layanan jasa yang bersifat sosio-ekonomi (non-profit), namun mengingat implementasi dan pengembangan sistem teknologi informasi memrlukan biaya yang (relatif) tinggi, maka sedapat mungkin didayagunakan untuk pengembangan layanan informasi yang menguntungkan (bisnis informasi di perpustakaan). Suhernik, S.Sos; Mahasiswa S2 Bid. Ilmu Informasi dan Perpustakaan UNPAD.

Mechanical Alloying of Mg2Ni Hydrogen Storage Alloy

After milling for 20 days, Mg2Ni has produced about 36 J.1mparticles as measured by particle size distribution and scanning electron microscopy. At this stage Mg2Ni alloy phases was formed as proven by X-ray diffraction. Energy-dispersive analysis analyses show that the elemental percentage of Mg and Ni is 67.8 % and 32.2 %, respectively. Those which are suitable for use as hydrogen storage alloy in nickel metal hydride batteries. Keywords: Mechanical Alloying, Mg2Ni alloy, X-ray diffraction. A. Azmin Mohamad; School of Materials and Mineral Resources Engineering, Universiti Sains Malaysia 14300 Nibong Tebal, Penang, Malaysia

Fractal Studies on Titanium-Silica Aerogels using SMARTer

Power-law scattering approximation has been employed to reveal the fractal structures of solid-state titanium-silica aerogel samples. All small-angle neutron scattering (SANS) measurements were performed using 36 meters SANS BATAN spectrometer (SMARTer) at the neutron scattering laboratory (NSL) in Serpong, Indonesia. The mass fractal dimension of titanium-silica aerogels at low scattering vector q range increases from -1.4 to -1.92 with the decrease of acid concentrations during sol-gel process. These results are attributed to the titanium-silica aerogels that are growing to more polymeric and branched structures. At high scattering vector q range the Porod slope of -3.9 significantly down to -2.24 as the roughness of particle surfaces becomes higher. The cross over between these two regimes decreases from 0.4 to 0.16 nm,l with the increase of acid concentrations indicating also that the titanium-silica aerogels are growing.E. Giri Rachman Putral, A. lkram\ Bharotol, E. Santosol, T. Chiar Fang2,N. Ibrahim2, A. Aziz Mohamed3 1 Neutron Scattering Laboratory, BATAN, Kawasan Puspiptek Serpong, Tangerang 15314, Indonesia 2 Department of Physics, Faculty of Science Universiti Teknologi Malaysia (UTM), 81310 Skudai, lohor, Malaysia 3 Materials Technology Group, Industrial Technology Division Agensi Nuklear Malaysia, 43000 Kajang, Malaysia Keywords: SANS, aerogels, fractals, power-law scattering.

Effect of Co-doping on Microstructural, Crystal Structure and Optical Properties of Tit-xCox02Thin films Deposited

Ti1_xCOx02 thin films have been grown on n-type Si(lOO) substrates by metal organic vapor deposition (MOCVD) using titanium (rV) isopropoxide (TTIP) and tris (2,2,6,6-tetramethyl-3, 5-heptanedionato) cobalt (III) as metal organic precursors. The parameter deposition, such as: bubbler temperature of TTIP Tb(Ti) = 50°C; substrate temperature Ts = 450°C; bubbler pressure Pb(Ti) = 260 Torr; flow rate of Ar gas through mp precursor Ar(Ti) = 100 sccm (standard cubic centimeters per minute) and flow rate of oxygen gas O2 = 60 secm were found as optimal deposition parameters. The thin films deposited were have rutile (002) crystal plane, whereas those deposited at other parameter were mixing of anatase and rutile phases. Co dopant with concentration of up to 5.77% was not changes the structure ofTi02. Increase of Co incorporated in thin films was decreasing of band-gap energy. Keywords: Crystalline orientation, Ti02, Ti1_xCOx02, MOCVD. E. Supriyantol,2, H. Sutantol,3, A. Subagio1,3,H. Saragihl, M. Budimanl,P. Arifinl, Sukimol and M. Barmawil 1Laboratory for Electronic Material Physics, Department. of Physics, Intitute of Technology Bandung, JI. Ganesha 10, Bandung 40132, Indonesia 2Department of Physics, Jember University, JI. Kalimantan III/25, Jember (68121), Indonesia 3Department of Physics, Diponegoro University, Jt. Tembalang Semarang, Indonesia

Application of X-ray and Neutron Scattering Techniques in Materials Research: Lithium Batteries and Electronic

X-ray and neutron powder diffraction provide complementary information on the structures of inorganic complex oxides, primarily because of the different dependence of atomic scattering power, or scattering length, on atomic number. Neutron diffraction is particularly useful for characterising novel lithium transition metal oxides which have applications in prototype advanced lithium battery systems. Thus, it is possible to establish conduction pathways for mobile Li+ ions and to distinguish between transition metal ions in ordered spinel structures such as Li2NiMn30s, which has a charge-discharge potential of 4.7V. An additional feature of such materials is oxygen non-stoichiometry in which their oxygen content depends on sample preparation conditions and temperature. This oxygen non-stoichiometry may be analysed by thermogravimetry and the transition metal oxidation states determined, in the solid state, by the X-ray absorption technique, XANES. Structural changes as a function of temperature may be followed by high temperature diffraction methods and as a function of lithium content during charging/discharging of lithium batteries by in situ synchrotron XRD. A range of examples of the applications of these techniques will be presented.A. R. West; University of Sheffield, Department of Engineering Materials,Sir Robert Hadfield Building, Mappin Street, Sheffield, SJ 3JD, United Kingdom

SANS Study of Micellar Structures on Oil Solubilization

Micellar structures of cationic alkyltrimethylammonium bromide (CnTAB) surfactants for different chain lengths (n=12, 14 and 16) in aqueous solution on the addition of two oils benzene and hexane have been studied by small-angle neutron scattering (SANS). Measurements have been performed for fixed 0.1 M concentration of surfactant and oil. It is found that the size and the aggregation number of the micelles increase on oil solubilization with increase in oil concentration. The effect is more pronounced for larger size of the micelles having longer chain length and also for the oil benzene than hexane. The axial ratio of the micelles shows a large increase and the effective charge on the micelles decreases on addition of oil. There is only a small increase in semiminor axis on addition of oil, which suggests that distribution of oil is uniform inside the micellar core. Keywords: Small-angle neutron scattering, micelles, oil solubilization. J. V. Joshit, V. K. Aswae and P. S. Goyal1
1 UGC-DAE CSR, Mumbai Centre, Bhabha Atomic Research Centre, Mumbai 400 085, India 2Solid State Physics Division, BhabhaAtomic Research Centre, Mumbai 400 085, India

Study of Mg-doped GaN Thin Films Grown on c-Plane Sapphire Substrate by Plasma Assisted Metalorganic

Mechanism of doping of Mg in GaN thin film grown on c-plane sapphire substrate by plasma assisted-metalorganic chemical vapor deposition (PA-MOCVD) method have been investigated. The growth was carried out at temperature of 680 DC, which flow rate of Cp2Mg as dopant source was varied of 0.003; 0.006; 0.009 and 0.012 sccm The Van der Pauw technique, X-ray diffraction (XRD) and scanning electron microscope (SEM) were used to characterize their electric, crystallographic and morphology properties. Hole concentrations of up to 1019 cm-3 have been observed for Mg-doped GaN films without any post-growth annealing. The XRD analysis showed change of the FWHMs for the (0002) orientation plane from Mg-doped GaN films. The difference of the atomic radius between Ga and Mg atoms causes lattice distortion in crystal. This lattice distortion generates dislocation and causes growth of the layer to be three-dimensional as showed on SEM images. Keywords: Mg-doped GaN, PA-MOCVD, Van der pauw technique, XRD, SEM. A. Subagio1,2, H. Sutanto1,2, E. Supriyanto1,3, M. Budiman1,P. Arifin1, Sukimo\ M. Barmawi1 1Laboratory for Electronic Material Physics, Dept. of Physics, ITB, Bandung 40132, Indonesia 2Dept. of Physics, Diponegoro University, Semarang, Indonesia 3Dept. of Physics, Jember University, Jember, Indonesia

Application of X-ray and Neutron Scattering Techniques in Materials Research: Lithium Batteries and Electronic Ceramics

X-ray and neutron powder diffraction provide complementary information on the structures of inorganic complex oxides, primarily because of the different dependence of atomic scattering power, or scattering length, on atomic number. Neutron diffraction is particularly useful for characterising novel lithium transition metal oxides which have applications in prototype advanced lithium battery systems. Thus, it is possible to establish conduction pathways for mobile Li+ ions and to distinguish between transition metal ions in ordered spinel structures such as Li2NiMn30s, which has a charge-discharge potential of 4.7V. An additional feature of such materials is oxygen non-stoichiometry in which their oxygen content depends on sample preparation conditions and temperature. This oxygen non-stoichiometry may be analysed by thermogravimetry and the transition metal oxidation states determined, in the solid state, by the X-ray absorption technique, XANES. Structural changes as a function of temperature may be followed by high temperature diffraction methods and as a function of lithium content during charging/discharging of lithium batteries by in situ synchrotron XRD. A range of examples of the applications of these techniques will be presented. A. R. West; University of Sheffield, Department of Engineering Materials, Sir Robert Hadfield Building, Mappin Street, Sheffield, SJ 3JD, United Kingdom