Prijo Sardjono
Pusat Penelitian Fisika-LIPI Kawasan Puspiptek Serpong Tangerang Selatan

Published : 6 Documents
Articles

Found 6 Documents
Search

PHASE ANALYSIS AND MAGNETIC PROPERTIES OF BaFe12O19/Nd2Fe14B COMPOSITE BY MECHANICAL MILLING PRODUCT Sardjono, Prijo; Adi, Wisnu Ari; Sebayang, Perdamaian; ., Muljadi
Jurnal Sains Materi Indonesia Vol 13, No 2 (2012): Februari 2012
Publisher : BATAN

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (41.834 KB)

Abstract

The synthesis and characterization of BaFe12O19/Nd2Fe14B composite by use mechanical milling has been performed. The result of refinement of X-ray diffractions showed that the sample consist of two phases namely BaFe12O19 and Nd2Fe14B phase with fraction mass were 79.89 and 20.11 wt%, respectively. The BaFe12O19 system magnetic materials have been formed with the crystal structure of hexagonal (space group P 63/m m c), lattice parameter are a = 5.9033(5) Å, b = 5. 9033(5) Å and c = 23.239(2) Å, α = β = 90o and γ = 120o, V = 701.3(1) Å3 and ρ = 5.7172 g.cm-3. The Nd2Fe14B system magnetic materials have been formed with the crystal structure of tetragonal (space group P 42/m n m), lattice parameter are a = 8.865(8) Å, b = 8.865(8) Å and c = 12.269(1) Å, α = β = γ = 90o, V = 964.3(1) Å3 and ρ = 7.7508 g.cm-3. The magnetic properties result of Nd2Fe14B shown that the sample has the coercive field and remanence magnetization are 7984 Oe and 5250 Gauss, respectively. The BaFe12O19 are 1625 Oe and 1190 Gauss, respectively. And the BaFe12O19- Nd2Fe14B composite increase to become 2650 Oe and 1580 Gauss, respectively. We conclude that the process of mixing between BaFe12O19 and Nd2Fe14B is not affect the change of each phase. The BaFe12O19 particle can be use as the shielding of the Nd2Fe14B particle from it’s the corrosion properties. The BaFe12O19 magnetic material has a stable structure at room temperature, so that this structure was not easy of change after mix with the Nd2Fe14B particles.Keywords: BaFe12O19/Nd2Fe14B, Mechanical milling, Crystal structure, Magnetic properties.
SYNTHESIS OF MAGNETIC MATERIALS PSEUDOBROOKITE Fe2TiO5 FROM LOCAL RESOURCES OF MINERAL Sardjono, Prijo; Adi, Wisnu Ari; ., Sudirman
Jurnal Sains Materi Indonesia Vol 14, No 3 (2013): April 2013
Publisher : BATAN

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (41.834 KB)

Abstract

The synthesis and characterization of magnetic materials pseudobrookite Fe2TiO5 from local resources of iron sand has been performed. Iron sand mineral is obtained from the coast of Banten. Iron sand is prepared by mechanical milling technique to obtain a small particle size. Then sand iron is carried out leaching and magnetic seperator to separates non-magnetic impurities. And then the separation results with magnetic separator is added TiO2 according to the rules of stoichiometric tomade magneticmaterial pseudobrookite Fe2TiO5. Synthesis of pseudobrookite Fe2TiO5 use solid state reaction through a process of mechanical milling and sintered at a temperature of 1000 °C for 5 hours. Refinement results of X-Ray Diffraction pattern showed that the magnetic material pseudobrookite Fe2TiO5 has been formed of good with the crystal structure of orthorombic (space group C m c m), lattice parameters a = 3.7233(5) Å, b = 9.774(1) Å and c = 9.968(1) Å, α = β = γ = 90o, the unit cell volume of V = 362.8(1) Å3 and atomic density of ρ = 4.178 g.cm-3. The measurement results of the magnetic properties indicate that the pseudobrookite Fe2TiO5 is soft magnet, and had coercivity field and remanence magnetization are 461 Oe and 0.2 emu/g, respectively. We concluded that this study has successfully made a magnetic material pseudobrookite Fe2TiO5 from local resources of iron sands.Keywords: Iron sand, Magnet, Pseudobrookite, Fe2TiO5, Crystal structure, Microstructure
SINTESIS BAHAN MAGNETIK PSEUDO BROOKITE Fe2TiO5 BERBASIS SUMBER DAYA MINERAL LOKAL Sardjono, Prijo; Adi, Wisnu Ari; Sudirman, Sudirman
Jurnal Sains Materi Indonesia Vol 14, No 3: APRIL 2013
Publisher : BATAN

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (461.355 KB) | DOI: 10.17146/jsmi.2013.14.3.4416

Abstract

SINTESIS BAHAN MAGNETIK PSEUDO BROOKITE Fe2TiO5 BERBASIS SUMBER DAYA MINERAL LOKAL. Telah dilakukan sintesis dan karakterisasi bahan magnet pseudobrookite Fe2TiO5 dari sumber daya alam lokal pasir besi. Mineral pasir besi diperoleh dari pesisir pantai Banten. Pasir besi ini dipreparasi dengan teknik mechanical milling untuk memperoleh ukuran partikel yang kecil. Kemudian pasir besi hasil milling dilakukan leaching dan seperator magnetic untuk menghilangkan pengotor-pengotor non magnetik. Hasil pemisahan dengan separator magnetic ditambahkan TiO2 sesuai kaidah stoikiometri untuk dibuat bahan magnet pseudobrookite Fe2TiO5. Sintesis pseudobrookite Fe2TiO5 menggunakan metode reaksi padatan melalui proses mechanical milling dan di sintering pada suhu 1.000 oC selama 5 jam. Hasil refinement dari pola difraksi sinar-X menunjukkan bahwa telah terbentuk bahan magnet pseudobrookite Fe2TiO5 dengan struktur kristal orthorombik (grup ruang C m c m), parameter kisi a = 3,7233(5) Å; b = 9,774(1) Å dan c = 9,968(1) Å, α  = β = γ = 90o, volume unit sel sebesar V = 362,8(1) Å3 dan kerapatan atomik sebesar ρ = 4,178 g.cm-3. Hasil pengukuran sifat magnetik menunjukkan bahwa pseudobrookite Fe2TiO5 hasil sintesis bersifat soft magnet dengan medan koersivitas dan magnetisasi remanen berturut-turut adalah 461 Oe dan 0,2 emu/g. Disimpulkan bahwa telah berhasil dibuat bahan magnet pseudobrookite Fe2TiO5 dari bahan baku sumber daya alam lokal pasir besi
ANALISIS FASA DAN SIFAT MAGNETIK PADA KOMPOSIT BaFe12O19/NdFe14B HASIL MECHANICAL MILLING Sardjono, Prijo; Adi, Wisnu Ari; Sebayang, Perdamaian; Muljadi, Muljadi
Jurnal Sains Materi Indonesia Vol 13, No 2: FEBRUARI 2012
Publisher : BATAN

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (575.101 KB) | DOI: 10.17146/jsmi.2012.13.2.4721

Abstract

ANALISIS FASA DAN SIFAT MAGNETIK PADA KOMPOSIT BaFe12O19/NdFe14B HASIL MECHANICAL MILLING. Telah dilakukan analisis fasa dan uji sifat magnetik pada bahan komposit magnet BaFe12O19/NdFe14B hasil mechanical milling menggunakan difraksi sinar-X dan GmbH Permagraph. Hasil refinement dari pola difraksi sinar-X menunjukkan bahwa sampel terdiri dari 2 fasa, yaitu fasa BaFe12O19 dan fasa NdFe14B. Sedangkan fraksi massa dari fasa BaFe12O19 dan fasa NdFe14B berturut-turut sebesar 79,89 % dan 20,11 %. Sampel bahan magnet BaFe12O19 dengan struktur kristal heksagonal (space group P 63/m m c), parameter kisi α = 5,9033(5) Å, b = 5,9033(5) Å dan c = 23,239(2) Å, α = β = 90o dan  = 120o, V = 701,3(1) Å3 dan  = 5.7172 g.cm-3. NdFe14B dengan struktur kristal simetri tetragonal (space group P 42/m n m (No. 136)) dengan parameter kisi sebesar a = 8,865(8) Å, b = 8,865(8) Å dan c = 12,269(1) Å, α = β = γ = 90o, V = 964,3(1) Å3 dan ρ = 7,7508 g.cm-3. Hasil pengukuran sifat magnetik menunjukkan bahwa bahan magnet NdFe14B sebelum dimilling memiliki medan koersivitas dan medan magnet rimanen berturut turut adalah 7984 Oe dan 5250 Gauss. Sedangkan untuk bahan magnet BaFe12O19 berturut-turut adalah 1625 Oe dan 1190 Gauss. Setelah dimilling selama 30 jam, medan koersivitas dan medan magnet rimanen meningkat di atas bahan magnet BaFe12O19 berturut-turut adalah 2650 Oe dan 1580 Gauss. Disimpulkan bahwa proses pencampuran ini tidak memberikan dampak rusaknya struktur fasa masing-masing. Partikel-partikel BaFe12O19 dapat dijadikan sebagai pelindung dari partikel-partikel NdFe14B yang memiliki sifat yang sangat korosif pada suhu kamar. Fasa BaFe12O19 ini relatif stabil pada suhu kamar sehingga partikel-partikel BaFe12O19 tidak mudah berubah setelah bercampur dengan partikel-partikel NdFe14B.
EFFECT OF WET MILLING TIME OF Nd-Fe-B FLAKES MATERIALS ON PARTICLE SIZE, MICROSTRUCTURE, AND MAGNETIC PROPERTIES Sardjono, Prijo; Muljadi, Muljadi; Suprapedi, Suprapedi; Djauhari, Nenen Rusnaeni
Teknologi Indonesia Vol 39, No 2 (2016)
Publisher : LIPI Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (16.054 KB) | DOI: 10.14203/jti.v39i2.292

Abstract

The refining of Nd-Fe-B alloy flakes has been done by a wet mechanical milling method using a ball mill. This process is used to produce a fine powder for making permanent magnet materials. The variation of milling time was 16, 24, 48 and 72 hours and a milling medium was used a toluene (pa- Emerck)) to protect the particle from oxidation during the milling process. After milling processes, the samples' distribution particle size were measured by using Particle Size Analyzer (PSA). Microstructure analysis has been conducted by using X-ray diffractometer (XRD) and Scanning Electron Microscope (SEM/EDX) for samples after and before milling. Vibrating Sample Magnetometer (VSM) was used to measure magnetic properties. The characterization results show that the refining process with the wet ball mill obtained finest powder with average size about 1.49 μm for milling time of 48 hours. According to SEM/EDX and XRD analysis, it shows that the crystal structure of the sample before milling was different compared to the sample after milling. It is found new magnetic phase with formula Nd2 Fe14 B. The magnetic properties of sample after milling 48 hrs is higher than that of sample before milling.
PENGARUH WAKTU DRY MILLING TERHADAP KARAKTERISTIK DAN SIFAT MAGNET PERMANEN ND-FE-B William, William; Simbolon, Tua Raja; Ginting, Herli; Sardjono, Prijo; Muljadi, Muljadi
Spektra: Jurnal Fisika dan Aplikasinya Vol 1 No 1 (2016): SPEKTRA: Jurnal Fisika dan Aplikasinya, Volume 1 Nomor 1, Agustus 2016
Publisher : Program Studi Fisika Universitas Negeri Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (281.938 KB) | DOI: 10.21009/SPEKTRA.011.03

Abstract

Abstrak Telah dilakukan proses penghalusan serpihan NdFeB dengan menggunakan metode dry milling dalam atmosfir gas inert dengan menggunakan gas Nitrogen (N2) dengan bahan awal yang digunakan berupa serpihan NdFeB dengan waktu milling yang divariasikan selama 8 jam, 16 jam, 24 jam dan 48 jam. Besaran magnetik yang diukur adalah koersivitas (Hc), induksi remanensi magnetik (Br) dan energi produk maksimum (BHmaks). Proses preparasi sampel dimulai dengan penghalusan serpihan dengan berbagai variasi waktu milling, dicetak dengan gaya 7 tonf selama 2 menit, dan dengan ditambahkan bahan perekat celuna sebanyak 3 wt%, hingga membentuk pelet dengan diameter ±1,6 cm. Selanjutnya sampel pelet di heat treatment selama 1 jam pada suhu 170ᵒC dan setelah itu dilakukan coating pada sampel. Sampel pelet yang telah melalui proses heat treatment, dimagnetisasi dengan impulse magnetizer pada tegangan 1500V DC. Sampel pelet yang telah dimagnetisasi diukur fluks density menggunakan Gaussmeter. Dari nilai densitas fluks magnet sampel, diperoleh sampel terbaik yaitu sampel hasil milling selama 48 jam pada suhu heat treatment 170ᵒC dan diperoleh fluks magnet sebesar 485,8 Gauss. Koersivitas pelet NdFeB yaitu 1,171 kOe dan BHmaks sebesar 0,62 MGOe. Kata-kata kunci: NdFeB, heat treatment, dry milling, gas inert Abstract Particle refining process of flakes NdFeB by dry milling method within an inert gas atmosphere using Nitrogen gas (N2) with based material was flakes NdFeB and with milling time parameters were variated for 8 hours, 16 hours, 24 hours and 48 hours had been done. The measured magnetic properties were coercivity (Hc), remanence (Br) and maximum energy product (BHmax). The preparation raw material process was started with particle refining with milling time variety, then it was pressed with 7 tonf force for 2 minutes and with added adhesive celuna as much as 3 wt% up to become pellets form with a diameter ±1.6 cm. Further the pellet samples were given heat treatment for 1 hour at temperature 170ᵒC and after that all the samples were coated. Pellet samples that have been done heat treatment, were magnetized with the impulse magnetizer in 1500V DC voltage. Pellet sample that had been magnetized ,its flux density was measured by using a Gaussmeter. From the magnetic flux density sample value, the best sample that obtained was the sample in milling time for 48 hours at heat treatment’s temperature was 170ᵒC and obtained magnetic flux density at 485.8 Gauss. The NdFeB pellet coercivity was 1.171 kOe and the BHmax was 0.62 MGOe. Keywords: NdFeB, heat treatment , dry milling , inert gas