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Sintering Effect on the Microstructure And Magnetic Properties of Co-Alxoy Composite Compound Mulyaningsih, Sri; Purwanto, Setyo; Mujamilah, Mujamilah; A. Adi, Wisnu; Manaf, Azwar
IPTEK The Journal for Technology and Science Vol 19, No 2 (2008)
Publisher : Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j20882033.v19i2.154

Abstract

Research on sintering effect on the micro structure and the magnetic properties of composite Co-AlxOy materials has been done. The experiment was carried out by high energy milling (HEM) to refine Co and Al sample powder, followed by sintering process. The composition of sample was Co73Al27 wt% with weight ratio to the ball was 1:2.7. The milling time was varied within 4.5, 12 and 20 hours, while sintering process was conducted at 384ºC and 484ºC. Several new peaks were found after sintering process and identified as a Co-Al2O4 compound. The experiment data shows the saturation magnetization Ms value was decline for the entire sample by the sintering process. The Mr value for the 12h milling was remind stable about 9 emu/gr but, for 4.5 milling was decline from 17.5 to 9.2 and 6.2 emu/gr , while for 20h milling from 13,5 to 9.25 and 8 emu/gr. No visible changes in the microstructure are observed.
STRUCTURE ANALYSIS OF SINGLE PHASE SISTEM Ba1-XLaXMnO3 (0 < X < 0.3) Manaf, Azwar; Adi, Wisnu Ari
Jurnal Sains Materi Indonesia Vol 14, No 2 (2013): Januari 2013
Publisher : BATAN

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Abstract

The synthesis and characterization of La1-XBaXMnO3 with (x = 0, 0.1, 0.2 and 0.3) magnetic materials by mechanical alloying process have been carried out. This magnetic materials is prepared by oxides, namely BaCO3, La2O3, and MnCO3. The mixture was milled for 10 hours then sintered at a temperature of 1,000 °C for 10 hours. The refinement results of X-Ray Diffraction pattern of Lanthanum manganite substituted with Barium for x = 0.1 and 0.2 showed that the sample consisted of single phase, namely, La0.9125MnO3 phase. LaMnO3 phase has a monoclinic structure (I12/a1) with lattice parameters a = 5.4638(7) Å, b = 5.5116(6) Å and c = 7.768(1) Å, α = β = 90o and γ = 90.786(9)o, the unit cell volume of V = 233.93(3) Å3, and the atomic density of ρ = 6.449 g.cm-3. The concluded that ability of Barium atom substitution in the Lanthanum atom in this system only up to the limit x ~ 0.2 formed the Ba0.2La0.8MnO3 structure. The addition of the element bariumfurthermore (x &gt; 0.2) will form two phases, namely La0.8Ba0.2MnO3 and BaMnO3 phases.Keywords: Ba-La Manganite, Crystal structure, Magnetic.
M-TYPE BARIUM HEXAFERRITE MAGNETIC MATERIAL FOR ANTI RADAR MATERIALS AT S BAND FREQUENCY ., Priyono; Manaf, Azwar
Jurnal Sains Materi Indonesia Vol 11, No 2 (2010): Februari 2010
Publisher : BATAN

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Abstract

In this paper, preparation and characteristic evaluation of microwave absorber materials of BaFe12-2xMnxTixO19 (x = 0.0 - 1.5) compositions are discussed. The absorber material was obtained by a co-substitution of Mn and Ti to Fe in a Barium Hexaferrite (BaO.6Fe2O3) basic compound through a mechanical alloying process. In this respect, a co-substitution of Mn and Ti ions for Fe was applied to Fe2O3 component at a temperature ~ 1,300 °C. The substituted alloy component was further alloyed mechanically with BaCO3 to form M-Type hexaferrite after the solid state reaction. Identification of X-Ray diffraction peaks for the mechanically alloyed materials indicates confidently that a single phase BaFe12-x-yMnxTiyO19 material was formed. Materials characterization is covering the average grain sizes and absorption of microwaves in the frequency range 1-6 GHz. Absorption with a relatively high coefficient at frequencies ~ 2,000 MHz and ~ 3,500 MHz within the available frequency range was obtained. It is shown that the co-substitution of Mn and Ti ion able to widen the absorption frequency especially in the frequencies of about 3,500 MHzKeywords: Radar Absorber Materials (RAM), Type-M barium hexaferrites, Grain size, S-band frequency.
Isothermal and non-isothermal crystallization Kinetic behavior of zinc-ferrite formation in theLow temperature flow injection co-precipitation synthesis reactor Sasito, Edie; Soegijono, Bambang; Manaf, Azwar
Jurnal Spektra Vol 14, No 2 (2013): Spektra: Jurnal Fisika dan Aplikasinya
Publisher : Jurnal Spektra

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Abstract

The kinetic behavior of zinc -ferrite crystallization process has been studied by co-precipitation of chlorine salt and alkaline solution. Either the parameter of temperature rate variation, pH previous of reactant and pH alkaline solution results non isothermal process was described by Ozawa equation,. There are significantly deferent in the taking both isothermal and non isothermal data. In the non- isothermal there are just oneexperiment can be sufficiency to reveal any crystal forming parameters but in the isothermal needs several different temperature experiments to reveals the parameter of crystal forming . In this research have be done one time non -isothermal experiment at means temperature 40 0C with temperature increase from 49 0C to 530C, and four time isothermal experiments at means temperature 60 0C,70 0C and 80 0C respectively. The sampling of experiment data have be done effectively using pH real- time video data logger. As a result the energy forming of the zinc ferrite both isothermal and non-isothermal are -4.27kcal/.mol,5.61kcal/mol respectively. The other kinetic parameter of crystallization and crystalline mechanism of both processes will be discussed.Keywords:co-precipitation, zinc-ferrite, non-isothermal process, crystallization, crystalline mechanism, data logger, kinetic behavior, flow injection co-precipitation synthesis.
SINTESIS PIGMEN BESI OKSIDA BERBAHAN BAKU LIMBAH INDUSTRI BAJA (MILL SCALE) Rahman, Tito Prastyo; Sukarto, Agus; Rochman, Nurul Taufiqu; Manaf, Azwar
Jurnal Fisika Vol 3, No 1 (2013)
Publisher : Jurnal Fisika

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Abstract

Limbah industri baja (mill scale) digunakan sebagai alternatif bahan baku pigmen besi oksida. Kajian ilmiah ini menjelaskan proses pembuatan pigmen besi oksida melalui metode presipitasi dengan media air. Pigmen besi oksida yang menjadi target yaitu pigmen kuning goethit ( -FeOOH) dan merah hematit ( -Fe2O3). Goethit diperoleh dengan presipitasi menggunakan amonia dari proses awal terbentuknya ferricssulfat hasil reaksi asam sulfat (H2SO4) dengan limbah mill scale, sedangkan hematit diperoleh dengan proses pemanasan goethit pada temperatur 5000C dan 9000C. Analisa XRD digunakan untuk mengetahui senyawa pigmen yang terkandung dan penggunaan DTA untuk mengetahui pola perubahan fasa akibat proses pemanasan fasa goethit. Analisa warna pigmen menggunakan collorimetri L*a*b System. Warna pigmen yang diperoleh mempunyai tinting strength yang masih kurang dibandingkan dengan pigmen impor.
Magnetic Field Effects on CaCO3 Precipitation Process in Hard Water Saksono, Nelson; Bismo, Setijo; Krisanti, Elsa; Manaf, Azwar; Widaningrum, Roekmijati
Makara Journal of Technology Vol 10, No 2 (2006)
Publisher : Directorate of Research and Community Services, Universitas Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.7454/mst.v10i2.118

Abstract

Magnetic treatment is applied as physical water treatment for scale prevention especially CaCO3, from hard water in piping equipment by reducing its hardness.Na2CO3 and CaCl2 solution sample was used in to investigate the magnetic fields influence on the formation of particle of CaCO3. By changing the strength of magnetic fields, exposure time and concentration of samples solution, this study presents quantitative results of total scale deposit, total precipitated CaCO3 and morphology of the deposit. This research was run by comparing magnetically and non-magnetically treated&nbsp; samples. The results showed an increase of deposits formation rate and total number of precipitated CaCO3 of magnetically treated samples. The increase of concentration solution sample will also raised the deposit under magnetic&nbsp; field. Microscope images showed a greater number but smaller size of CaCO3 deposits form in magnetically treated samples, and aggregation during the processes. X-ray diffraction (XRD) analysis showed that magnetically samples were dominated by calcite. But, there was a significant decrease of calcite’s peak intensities from magnetized&nbsp; samples that indicated the decrease of the amount of calcite and an increase of total amorphous of deposits. This result&nbsp; showed that magnetization of hard water leaded to the decreasing of ion Ca2+ due to the increasing of total CaCO3 precipitation process.
Effects of Ph on Calcium Carbonate Precipitation Under Magnetic Field Saksono, Nelson; Yuliusman, Yuliusman; Bismo, Setijo; Soemantojo, Roekmijati; Manaf, Azwar
Makara Journal of Technology Vol 13, No 2 (2009)
Publisher : Directorate of Research and Community Services, Universitas Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.7454/mst.v13i2.165

Abstract

Magnetic field effect on CaCO3 precipitation is the key parameter in evaluating the effectiveness of Anti-scale Magnetic&nbsp;Treatment (AMT). The purpose of this study was to investigate magnetic fields influence on CaCO3 precipitation in&nbsp;high and low super-saturated CaCO3 solution by varied pH CaCO3 solution using circulation flow fluid system. The&nbsp;observation results in the high super saturated solution (pH 8.5) showed the increase of precipited CaCO3 in magnetized&nbsp;solutions compared to those in non-magnetic solution during circulation process. In the low super-saturated CaCO3&nbsp;solution (pH 6.4) it was found that magnetic treatment increased CaCO3 precipitation after circulation process. In high&nbsp;super-saturated solution, magnetic field strengthens ion interactions, which reduce precipitation during circulation&nbsp;process. However, in low super-saturated CaCO3 solution, magnetic field weakens hydrate ion interaction which&nbsp;indicated by decreasing of the conductivity of solution. It increases the precipitation of CaCO3 after the circulation of&nbsp;magnetization process has completed.
Formation of CaCO3 Particle and Conductivity of Na2CO3 and CaCl2 Solution Under Magnetic Field on Dynamic Fluid System Saksono, Nelson; Bismo, Setijo; Widaningroem, Roekmijati; Manaf, Azwar
Makara Journal of Technology Vol 15, No 1 (2011)
Publisher : Directorate of Research and Community Services, Universitas Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.7454/mst.v15i1.207

Abstract

Hard&nbsp; water&nbsp; causes&nbsp; the&nbsp; CaCO3&nbsp; scale&nbsp; formation&nbsp; on&nbsp; the&nbsp; pipe&nbsp; walls and&nbsp; heat&nbsp; exchanger&nbsp; equipments&nbsp; in&nbsp; industrial&nbsp; or domestic&nbsp; water&nbsp; processes.&nbsp; A&nbsp; great&nbsp; number&nbsp; of&nbsp; experimental&nbsp; researches&nbsp; on&nbsp; the&nbsp; prevention&nbsp; of the&nbsp; CaCO3&nbsp; precipitation process&nbsp; by&nbsp; magnetic&nbsp; field&nbsp; have&nbsp; been&nbsp; carried&nbsp; out.&nbsp; In&nbsp; this&nbsp; research,&nbsp; Na2CO3&nbsp; and&nbsp; CaCl2&nbsp; solutions&nbsp; was&nbsp; magnetized&nbsp; in&nbsp; the circulated&nbsp; flow&nbsp; condition&nbsp; (dynamic&nbsp; fluid&nbsp; system).&nbsp; The&nbsp; velocity&nbsp; of&nbsp; fluid&nbsp; and&nbsp; the&nbsp; circulation&nbsp; time&nbsp; was&nbsp; modified&nbsp; to examine&nbsp; its influences&nbsp; to&nbsp; the&nbsp; magnetization&nbsp; process.&nbsp; CaCO3&nbsp; content&nbsp; was measured&nbsp; by&nbsp; titration&nbsp; method&nbsp; of&nbsp; EDTA complexometry.&nbsp; Conductivity&nbsp; test&nbsp; was&nbsp; conducted&nbsp; to&nbsp; find&nbsp; out&nbsp; hydrate&nbsp; ion&nbsp; bonding.&nbsp; The&nbsp; results&nbsp; showed&nbsp; that magnetization increased the CaCO3 formation and the optimum process reaches for 10 minutes circulation on 0.554 m/s of flow rate. Magnetic field decreases the conductivities of Na2CO3 and CaCl2&nbsp; solution, hence reduced the ion hydrate bonding. These results showed that magnetization on Na2CO3 and CaCl2 ionic solution was effective in controlling the CaCO3 formation by increasing CaCO3 precipitation.
MICROWAVE ABSORBING PROPERTIES OF LaMn1-x NixO3. Saptari, Sitti Ahmiatri; Manaf, Azwar; Kurniawan, Budhy
Jurnal Sains Materi Indonesia Vol 15, No 4: JULI 2014
Publisher : BATAN

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (230.577 KB) | DOI: 10.17146/jsmi.2014.15.4.4335

Abstract

MICROWAVE ABSORBING PROPERTIES OF LaMn1-x NixO3. The doped lanthanum manganites have unusual magnetic and transport properties, which makes it possible for this material to be used for microwave absorbing. In this study, LaMn1-xNixO3 (x = 0, 0.02, 0.04, and 0.06) were prepared by solid state reaction method as microwave absorption material. The crystal structure and magnetic properties were characterized byX-Ray Diffractometer (XRD) and Vibrating SampleMagnetometer (VSM), respectively. Refinement results of X-Ray diffraction pattern using High Score Plus Software showed that the samples with various x = 0 to x = 0.04 had a single phase with monoclinic crystal structure, while the sample with x = 0.06 had two phases with monoclinic and hexagonal structures. Hysteresis loops showed that the LaMn1-xNixO3 (x = 0, 0.02, 0.04, and 0.06) samples are soft magnetic materials. Microwave absorption properties were investigated in the frequency range of 8-12 GHz using Vector Network Analyzer (VNA). An optimal reflection loss of -8.85 dB is reached at 11.58 GHz for x = 0.04 with sampel thickness of 2 mm.
PHYSICAL CHARACTERISTICS AND MAGNETIC PROPERTIES OF BAFE12O19/SRTIO3 BASED COMPOSITES DERIVED FROM MECHANICAL ALLOYING Widodo, Rahmat Doni; Manaf, Azwar
Sainteknol : Jurnal Sains dan Teknologi Vol 14, No 2 (2016): December 2016
Publisher : Unnes Journal

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15294/sainteknol.v14i2.8994

Abstract

Barium hexaferrite and strontium titanate are well established permanent magnet and piezoelectric materials which are technologically and scientifically attractive due to their potential for various applications in the field of magnetic electronics functional materials. However, the material properties for both require a careful control of grain structure as well as microstructure design to meet a specific application. In this work, we report some results of materials characterization especially particles and grains which were promoted during mechanical milling of a BaFe12O19/SrTiO3 composite system. These are including mean particle size characterization by Particle Size Analyzer and mean grain size determination by means of line broadenning analysis employing a step scanning counting in XRD apparatus for composite powders at various milling time up to 60 hours. It was found that the particle size of composite powders initially increased due to laminated layers formation of a composite and then decreased to an asymptotic value of ~8 μm as the milling time extended even to a relatively longer time. However, based on results of line broadening analysis the mean grain size of the particles was found in the nanometer scale. We thus believed that mechanical blending and milling of mixture components for the composite materials has promoted heterogeneous nucleation and only after successive sintering at 1100 oC the milled powder transformed into particles of nanograin. In thireport, microstructure as well as magnetic properties for the composite is also briefly discussed.