Masno Ginting

The synthesization of Fe3O4 magnetic nanoparticles based on natural iron sand by co-precipitation method for the used of the adsorption of Cu and Pb ions

Magnetic nanoparticles of Fe3O4 (magnetite) have been synthesized from natural sand iron by co-precipitation method. The nanoparticles were synthesized using HCl as solvent and NH3 as co-precipitate. The nanoparticles synthesized at 70°C in two different treatments. Sample without Polyethylene Glycol (PEG) 6000 noted by A and sample with PEG 6000 noted by B symbol. The measurement that have been done for both samples were XRD (X-ray diffraction), FTIR (Fourier Transform Infrared) Spectrometry, SEM (Scanning electron microscopy), VSM (Vibrating sample magnetometer) and SAA (Surface area analyzer). The results showed that both samples were having Fe3O4 phases. Particle size, coercivity and magnetic saturation of B samples were smaller than A samples. But the surface area of B sample was larger than A sample. Both samples were then used to adsorb Cu and Pb ions using shaker method. Adsorption analysis from Atomic Adsorption Spectroscopy (AAS) showed that B was more effectivein adsorbing metal ions than A. The adsorption value of Cu and Pb ions were 79 and 91% respectively.

Synthesis, Properties and Application of Glucose Coated Fe3O4 Nanoparticles Prepared by Co-precipitation Method

Synthesis of glucose coated Fe3O4 magnetic nanoparticles have been successfully prepared with co-precipitation method. Raw material of natural iron-sand was obtained from Buaya River, Deliserdang, Indonesia. The milled iron-sand was dissolved in HCl (37 mole %), and stirred in 300 rpm at 70°C for 90 minutes. Glucose was added to the filtered powder with varied content of 0.01, 0.02, and 0.03 mole, and precipitated by NH3 (25 mole%). After drying process, the final product subsequently was glucose coated magnetite (Fe3O4) nanoparticles. The characterizations performed were true density measurement, FTIR, VSM, XRD, BET, and adsorbent performance by AAS. The FTIR analysis showed that M-O (bending) with M=Fe (stretching vibration) with υ = 570.92 and 401.19 cm-1. While glucose coated well on nanoparticle Fe3O4, proved by functional groups C=O (stretching), M-O (stretching) and C-H (bending) with υ = 1404.17, 570.92, and 2368.58 cm-1, respectively. Single phase of magnetite (Fe3O4) structure was determined from XRD analysis with cubic spinel structure and lattice parameter of 8.396 A. The optimum conditions, obtained on the Fe3O4 nanoparticles with 0.01 mole of glucose addition, which has true density value of 4.57 g/cm3, magnetic saturation, M s = 35,41 emu/g, coercivity, H cJ = 83.58 Oe, average particle size = 12.3 nm and surface area = 124.88 m2/g. This type magnetic nanoparticles of glucose-coated Fe3O4 was capable to adsorbed 93.78 % of ion Pb. Therefore, the glucose-coated Fe3O4 nanoparticle is a potential candidate to be used as heavy metal removal from wastewater.

Synthesis and Characterization of Magnetic Elastomer based PEG-Coated Fe3O4 from Natural Iron Sand

Magnetic elastomer nanocomposite based PEG-coated Fe3O4 with silicone rubber binder have been prepared from natural iron-sand by using coprecipitation method. The samples were characterized by using X-ray Diffractometer, X-ray Fluorescence, Fourier Transform Infra-Red, tensile strength test, and Vibrating Sample Magnetometer to analyze the physical and magnetic properties. We observed that all samples were formed by single phase cubic spinel magnetite (Fe3O4) crystalline structure. The atomic bonding analysis by FTIR showed that the C-O-C and C-H ordering were understood as the PEG – Fe3O4 bonding characteristics. We have observed that the Young modulus of elastomer based PEG-coated Fe3O4 slightly decreased compared to the natural iron-sand based elastomer. The magnetic properties of PEG-coated Fe3O4 were known to be magnetically softer with the lowest coercivity without losing its magnetization saturation value. We propose that the PEG-coated Fe3O4 is a promising candidate to be applied as magnetorheological elastomer due to a good mechanical and magnetic characteristic and also promising as microwave absorbing materials.

Preparation and Characterization of Fe-Mn-doped Barium Hexaferrite Permanent Magnet

Barium Hexaferrite-based permanent magnets (BaFe12O19) was known for its high magnetic anisotropy and suitability in broad applications. Some dopants and atomic substitutions have been utilized to improve its properties for special purposes. In this paper, the Fe-Mn system was used as a dopant for preparing Fe-Mn-doped barium hexaferrite permanent magnet using mechanical alloying method. The physical properties of the samples, such as bulk density, and porosity were examined to study the effect of the dopant. In addition, the crystal structure and magnetic properties of the samples were analyzed using X-Ray Diffractometer (XRD) and Vibrating Sample Magnetometer (VSM), respectively. It is found that the addition of Fe-Mn into barium hexaferrite contributes on the appearance of minor phases such as iron oxide-based magnetite and hematite. In addition, the XRD peak shifted to smaller angle which is likely due to Mn ion substitution and lattice strain within the hexaferrite crystal. It is also observed that the magnetic properties of Fe-Mn-doped barium hexaferrite was inferior to that of the undoped samples. It means that the formation of magnetite and hematite from Fe-Mn dopant during the sintering process is dominant and results to the reduction of hard magnetic properties of the samples.

Effects of Sintering Holding Time on the Structural, Electrical and Magnetic Properties of Zn0.95Ni0.05O

Zn0.95Ni0.05O has been synthesized by mixing 5% mol of NiO into ZnO using solid state reaction and high-speed shaker mill method. The samples were sintered at 900 °C with holding time for 2, 4 and 8 hours. Crystal structure, electrical and magnetic properties of Zn0.95Ni0.05O were characterized by using XRD, I-V, C-V and VSM. XRD results showed that variation of holding time does not change the structure of ZnO and no other secondary phase observed. The value of lattice parameters (a and c) tends to decrease proportionally to the holding time. The Intensity value changes and the peak shifted to a higher 2θ angle due to holding time variation. In general, the conductance of Zn0.95Ni0.05O decreases and the magnetic properties decrease also as the holding time is increased.

Preparation and characterization of zinc oxide doped with ferrite and chromium

In this paper, the effect of doping concentrations of Fe and Cr on ZnO powder was studied by using X-ray diffraction (XRD). The ZnO was doped using solid state reaction method with High Speedshaker Mill (HSM) and continued with sintering at 900°C for 4 hours. Samples doped with Fe and Cr have polycrystalline hexagonal wurtzite structure. XRD pattern of ZnO doped with Fe is not far different from that with Cr. The intensity decrease and the peak shifted to a higher 2θ angle indicate the change in the crystal parameters such as lattice parameters, crystalline sizes, and d-spacing.In this paper, the effect of doping concentrations of Fe and Cr on ZnO powder was studied by using X-ray diffraction (XRD). The ZnO was doped using solid state reaction method with High Speedshaker Mill (HSM) and continued with sintering at 900°C for 4 hours. Samples doped with Fe and Cr have polycrystalline hexagonal wurtzite structure. XRD pattern of ZnO doped with Fe is not far different from that with Cr. The intensity decrease and the peak shifted to a higher 2θ angle indicate the change in the crystal parameters such as lattice parameters, crystalline sizes, and d-spacing.

PENGARUH KECEPATAN ROTOR DAN MAGNETIC FLUX DENSITY TERHADAP OUTPUT TEGANGAN GENERATOR AXIAL FLUX PERMANENT MAGNET

Pada penelitian ini akan dikaji pengaruh kecepatan putar rotor n dan kerapatan fluks magnet B r terhadap output tegangan, E rms melalui simulasi dan analisis pada generator axial flux permanent magnet (AFPM). Generator fluks aksial magnet permanen yang dibuat dalam penelitian ini adalah terdiri atas dua rotor yang menggunakan magnet permanen NdFeB dengan B r = 0.2 Tesla dan satu stator dengan jumlah 9 kumparan, 70 lilitan, dan 3 fase. Dari hasil ujicoba generator yang dibuat output tegangan mulai terbaca apabila kecepatan putaran > 228 rpm. Sedangkan dari hasil simulasi, tegangan dapat terbaca setelah putaran pertama. Pada kecepatan rotor 1000 rpm, korelasi antara kerapatan fluks magnet, B r terhadap output tegangan induksi generator Erms adalah E rms = 34.706 B r . Apabila kecepatan rotor ditingkatkan menjadi 1.5 kali, maka E rms juga akan meningkat sebesar 1.5 kalinya.

THE USE OF AN IMPORTED NdFeB MAGNET IN DESIGNING AND FABRICATING AXIAL FlUX PERMANET MAGNET GENERATOR

Axial flux generator that consists of two rotors and one stator has been engineered. The rotor consists of eight imported NdFeB permanent magnets with 6 x 4 x 0.7 cm dimension and remanant (Br) 1.1 Tesla. The stator with 300 mm diameter consists of a spoils with 80 mm diameter with 400 coils, and the diameter of copper wire is 0.5 mm, while the number of the spoil is varied. In this paper, the design and analysis for generator model has been done using 3DS MAX 2014 and Microsoft Visual Basic 2010 Express software, so that the right number of spoils in producing the optimal out put voltage (Erms) is obtained. From the experiment and simulation of axial flux permanent magnet (AFPM) generator, it has been obtained that there is correlation between the rotational speed (Vr in rpm) and the frequency and the voltage (Erms), which are given by equations i.e. frequency = 0.0667 Vr - 0.0001 and Erms = 0.4027 Vr + 3.2619, repectively. Meanwhile, the relation of the rotational speed and the number of spoils (Ns) to the outout voltage (Erms) is given by Erms = 0.0695 Ns Vr.

Magnetic Properties Evaluation of Fe-Al Nanocrystalline Alloys Fabricated by Mechanical Alloying Technique as a Function of Milling Time

Magnetic properties of nanocrystalline Fe50Al50 alloys prepared by mechanical alloying technique (using commercial Fe and Al powders as precursors) were studied in detail as a functions of the milling time ranging from 1 to 24 hrs. The structural analyses based on X-ray diffraction (XRD) and extended X-ray absorption fi ne structure spectroscopy (EXAFS) revealed that the alloying process took place after 12 hrs of milling time. Concerning the magnetic behavior, the data that were obtained from a superconducting quantum interference device (SQUID) showed that both the magnetic saturation (Ms) and the coercivity (Hc) depend strongly on the milling time. From the results that we obtain, we found out that by adjusting the milling time, is a key factor in obtaining an appropriate structural transformation and appropriate magnetization values.

Effect of CeO{sub 2} addition on the properties of FeAl based alloy produced by mechanical alloying technique

Iron aluminides based on FeAl is notable for their low materials cost, ease of fabrication and good corrosion, suffixation and oxidation resistance. However, the application based on these unique properties still require the development of Fe-Al based alloy since it shows some drawbacks such as a lack of high temperature strength and low ductility. To improve the mechanical properties of FeAl based alloy, ceria (CeO2) will be added to this compound. FeAl based alloy produced by the mechanical alloying (MA) technique. The developed specimens then assessed with respect to oxidation behaviour in high temperature, scale microstructure and hardness. The surface morphologies of the alloy evaluated and observed using scanning electron microscopy (SEM) with an energy dispersive X-ray spectroscopy (EDX). The phase structures of oxide scale formed on them were identified by X-ray diffraction (XRD). The results found that the FeAl intermetallic compound containing CeO2 0.5 wt.% is less pores and CeO2 1.0 wt.% is mor...