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SIFAT LISTRIK BAHAN KOMPOSIT FeXC1-X SEBELUM DAN SESUDAH IRADIASI SINAR- SAMPAI DOSIS 500 kGy Yunasfi, Yunasfi; Mustofa, Salim; Madesa, Tria
Jurnal Sains dan Teknologi Nuklir Indonesia Vol 12, No 1 (2011): Februari 2011
Publisher : BATAN

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ABSTRAK SIFAT LISTRIK BAHAN KOMPOSIT FeXC1-X SEBELUM DAN SESUDAH IRADIASI SINAR-g SAMPAI DOSIS 500 kGy. Telah dilakukan penelitian terhadap sifat listrik bahan komposit FeXC1-X sebelum dan sesudah iradiasi dengan sinar-g sampai dosis 500 kGy. Bahan komposit FeXC1-X dibuat dari campuran serbuk Fe dan serbuk grafit, dengan rasio komposisi (20:80, 50:50, dan 80:20) % berat dengan berat total 20 gram. Campuran masing-masing bahan komposit ini diproses milling dengan teknik High Energy Milling (HEM) selama 4,5 jam, kemudian dibuat dalam bentuk pelet dengan tekanan 5000 psi. Pada penelitian ini, diamati perubahan sifat listrik bahan komposit FeXC1-X setelah diiradiasi dengan sinar-g pada berbagai variasi dosis (50–500 kGy). Karakterisasi sifat listrik bahan komposit FeXC1-X dianalisis memakai LCR meter. Hasilnya menunjukkan bahwa nilai konduktivitas dan kapasitansi bahan komposit meningkat oleh adanya radiasi sinar-g. Nilai konduktivitas dan kapasitansi meningkat secara linear seiring dengan bertambahnya dosis radiasi sinar-g. Peningkatannya mencapai 4,5 % untuk nilai konduktivitas, dan 11,5 % untuk nilai kapasitansi setelah diirradiasi sampai dosis 50 kGy. Pada dosis maksimum (500 kGy), peningkatan nilai konduktivitas mencapai 41,5 %, dan nilai kapasitansi naik 47,5 % berat. Diperkirakan peningkatan nilai-nilai ini didapatkan karena adanya cacat (defect) yang terbentuk di dalam struktur bahan komposit FeXC1-X akibat interaksi radiasi sinar-g dengan bahan komposit sehingga menimbulkan perubahan pada sifat listrik bahan komposit FeXC1-X.   Kata kunci: irradiasi sinar-g, sifat listrik, komposit FeXC1-X     ABSTRACT ELECTRICAL PROPERTIES OF FeXC1-X COMPOSITE MATERIALS PRE AND POST g- IRRADIATION UP TO 500 kGy DOSE. Research about change of electrical properties of FeXC1-X composite materials pre and post g-irradiation up to 500 kGy dose was carried out. FeXC1-X composite materials were prepared by mixing Fe and graphite powders. The mixing ratios were 20:80, 50:50, and 80:20 % of weight, and total mixing weight was 20 grams. Each mixed sample was milled using High Energy Milling (HEM) for 4.5 hours, and afterwards the composite was formed into a pellet under a pressure up to 5000 psi. In this study, the changes in electrical properties of composite materials FeXC1-X after irradiated by g-rays at various doses (50-500 kGy) was observed. Characterization of electrical properties of composite materials FeXC1-X was analyzed using LCR meter. The result showed that the value of conductivity and capacitance of composite materials increased by the presence of g-ray. The value of conductivity and capacitance increases linearly with the increasing of g-ray doses. The increase of conductivity reaches 4.5%, and the increase of capacitance reaches 11.5% at 50 kGy. At max dose of 500 kGy, the increase was 41.5% for conductivity and 47.5% for capacitance. It is estimated that the increases were obtained because of defect formed inside of the FeXC1-X resulted from the interactions of g-ray with FeXC1-X, so it leads to the changes in electrical properties of FeXC1-X.   Keywords: g-ray irradiation, electrical properties, FeXC1-X composite  
GROWTH OF CARBON NANOTUBES WITH MILLING TECHNIQUE USING Fe AS A CATALYST. ., Yunasfi; Mustofa, Salim; ., Muflikhah
Jurnal Sains Materi Indonesia Vol 14, No 1 (2012): Oktober 2012
Publisher : BATAN

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Growing of carbon nanotubes (CNT) with a milling technique using particles Fe as grower catalyst has been done. Fe-C nano-sized powder mixture are prepared froma mixture of micron-sized graphite and Fe powders in a variety of weight percent Fe (1% to 5% by weight Fe), and then milled for 50 hours using a High Energy Milling (HEM) facility. X-ray diffraction pattern shows the presence of C (002), C (004) and C (110) peaks and Fe peaks of (101) and (200). Carbon peaks decrease in intensity with increasing wt%Fe and tend to becoming amorphous, while Fe peaks sharply increasing. Microstructure observation by TEM showed an initial growth of CNTs with dimensions affected by Fe content. The sample, containing 2%Fe, formed CNT structure better than other samples. CNT formation was also confirmed fromthe Raman spectrum showing the presence of the G-band at 1590 cm-1 and D-band peak at 1310 cm-1 with and D-band intensity, ID higher than IG and absence of RBM-band peak at low wave numbers. This condition is a typical spectrum for a material having a Multi Wall Carbon Nanotube (MWCNT) structure. The highest ratio of ID/IG for 2% Fe sample support the analysis of CNT-dimension from Transmission Electron Microscope (TEM) observation. In general, the data obtained in this study showed that Fe can serve as a catalyst for CNT growth.Keywords: Graphite, CNT, Milling technique, Precursor Fe.
GROWTH OF CARBON NANOTUBE BY APPLYING ION IMPLANTATION TECHNIQUE Mustofa, Salim; ., Yunasfi
Jurnal Sains Materi Indonesia Vol 13, No 2 (2012): Februari 2012
Publisher : BATAN

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The use of ion implantation technique for growing carbon nanotubes (CNT) has been studied. Implantation technique with its high and focused energy is used for implanting Ni+ ion, which can act as catalyst for CNT growth. CNT was grown by implantation of Ar(sup>+ and Ni+ ion to the nanostructured carbon thin film that were deposited on Si(100) substrate. The dose of ion implantation parameter was varied between 5 x 1015 to 1 x 1017 ion/cm2. After implantation, the phase identification by X-Ray diffraction (XRD) and observations of surface and cross section morphology of samples by Scanning Electron Microscopy (SEM) in order to investigate the growth of CNT were carried out. The XRD analysis shows the peak of C(002), Ni(010) and Si(100) on the C/Si thin film samples after ion implantation, which indicate the carbon filmstill in a crystalline structure. The peak of Ni(010) is slightly decreased with the increasing of ion dose. The observation by SEM shows that the greater the dose of implants, the more unflat surface found on a thin film.While from the observation of cross section, it was indicated that the higher dose implants, more clearly the growth of CNTs on the surface of C/Si thin film. CNT is predicted to grow as a result of interaction between ion radiations with carbon, leading to the formation of CNTs.Keywords: Thin Film, CNT, Ion Implantation Technique, Dose.
SYNTHESIS AND CHARACTERIZATION OF GRAPHITE NANOSTRUCTURE THIN FILM WITH SPUTTERING TECHNIQUE ., Yunasfi; Mustofa, Salim; ., Deswita
Jurnal Sains Materi Indonesia Vol 13, No 1 (2011): Oktober 2011
Publisher : BATAN

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Synthesis and characterization of graphite nanostructure thin film using the DC-sputtering technique has been carried out. Nanostructured graphite for target of deposition using DC-Sputtering technique has been prepared by milling technique using High Energy Milling (HEM) with the variation of milling time between 50 hours until 100 hours. First, the graphite target was prepared by doing a compaction using press machine to the nanostructured graphite powder got from milling process. Secondly, a thin film of graphite was fabricated using DC-Sputtering technique. The phase identification of nanostructured graphite thin film were carried out using X-Ray Diffraction (XRD), and the surface and cross section morphology of thin film were observed using Scanning Electron Microscopy (SEM). XRD identification shows the presence of peaks of Si(100) and C(002) in all conditions of preparing powder using for target, but a shift of the angel‘s peak to the left and the decreasing of peak intensity were found. While the observation using SEM to surface morphology of thin film shows that the form of thin films are mostly homogeneous, smooth and flat at the milling time of 50-75 hours. From the SEM photograph of cross section, it is shown that there is a tendency of the more commonly found particles of droplets on the surface of thin film with the increasing of milling process against the carbon powder as a constituent of pellets for the DC-Sputtering targets, especially in the case of C/Si thin film fabricated using target prepared by milling for 100 hours, the morphology of surface was worst.Keywords: Graphite Thin Film, Nanostructure, DC-Sputtering Technique, HEM, Carbon Target.
GROWTH OF CARBON NANOTUBE FROM NANOSTRUCTURED COMPOSITE OF Fe-C USING ION IMPLANTATION TECHNIQUE Mustofa, Salim
Jurnal Sains Materi Indonesia Vol 12, No 1 (2010): Oktober 2010
Publisher : BATAN

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Growth of carbon nanotube (CNT) from nanostructured composite of Fe-C has been carried out using ion implantation technique. The CNT developed here is expected to be used as an Integrated Sensor System, because CNT offer promises for future nano-electronic sensor applications, and reliably controlling CNT growth has been a big challenge. Nanostructured composite of Fe-C was prepared by milling for 50 hours. The size of Fe-C powder was determined from Scanning Electron Microscope (SEM) image. Milled powder then was compressed to get pellet form of Fe-C, and used as a target in fabricating thin film of Fe-C on Si(100) substrate using sputtering technique. Further, the ion implantation was done against the Fe-C thin film. The ion source using Argon gas, in order to make growth of CNT until the densitiy dose of 5 x 1015 ions/cm2. The phase of formed CNT was identified by X-Ray Diffractometer (XRD), the morphology of surface was observed by SEM. From this research, it has been showed that the milled composite of Fe-C has a powder size until nano order size. From XRD data, it is identified that only Fe and C peaks were confirmed. On the other hand, the observation on the surface of Fe-C thin film showed the growth of CNT.Keywords: Carbon Nanotube, Integrated Sensor System, Composite of Fe-C, Ion Implantation.
Effect of Mechanical Treatment on The Electrical Properties of Graphite Materials ., Yunasfi; Mustofa, Salim
Jurnal Sains Materi Indonesia Vol 11, No 3 (2010): Juni 2010
Publisher : BATAN

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Measurement of electrical properties of graphite materials as the mechanical treatment result with high energy milling (HEM) techniques was carried out. The carbon powder was milled using HEM by varying the milling time from 25 hours to 100 hours, and afterwards the graphite material was formed to a pellet under compaction up to 20 ton/cm2. The measurements result of electrical properties using LCR (Inductance, Capacitance, Resistance) meter showed that milling process to graphite causes the increasing of conductivity and capacitance values and these values were increasing with the increase of milling times. Before milling, the conductivity value is 3.5976 Siemens/cm and the value of capacitance is 0.2223 μF at 100 kHz frequence. Increasing of conductivity value reached 26% and capacitance value reached 66% after milling for 100 hours. These incresing are analized due to decreasing of graphite powder particle size causing by longer milling time and result in higher electrical conductivity.Keywords: Mechanical Treatment Graphite, Electrical Properties, Conductivity, High Energy Milling. 
PERUBAHAN SIFAT MAGNETIK BAHAN KOMPOSIT Fe-C OLEH RADIASI SINAR GAMMA Yunasfi,, Yunasfi,; Mustofa, Salim; Purwanto, Setyo; Mashadi, Mashadi; Madesa, Tria
Jurnal Sains Materi Indonesia Edisi Khusus Oktober 2007
Publisher : Center for Science & Technology of Advanced Material - National Nuclear Energy Agency of

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (474.298 KB) | DOI: 10.17146/jusami.2007.0.0.5137

Abstract

PERUBAHAN SIFAT MAGNETIK BAHAN KOMPOSIT Fe-C OLEH RADIASI SINAR GAMMA. Telah dilakukan penelitian terhadap perubahan sifat magnetik bahan komposit Fe-C oleh radiasi sinar gamma. Fe-C dibuat dari campuran serbuk Fe dan serbuk karbon, dengan rasio komposisi berat kandungan Fe dan karbon 50 % dan 50 %. Dalam penelitian ini, diamati perubahan sifat magnetik bahan komposit Fe-C setelah diiradiasi dengan sinar gamma pada dosis 250 kGy. Identifikasi struktur bahan komposit Fe-C yang telah diiradiasi dilakukan dengan metode XRD (X-Ray Diffractometer ) dan karakterisasi sifat magnetik dilakukan dengan menggunakan VSM (Vibrating Sample Magnetometer). Hasil identifikasi dengan metode XRD menunjukkan adanya penurunan intensitas difraksi setelah iradiasi sinar gamma. Hasil pengukuran kurva histeresis M-H dengan VSM, menunjukkan bahwa bahan komposit Fe-C setelah diiradiasi memiliki Hc (medan koersiv), Ms (magnetisasi saturasi) serta Mr (magnetisasi remanen) lebih rendah dibanding dengan kondisi sebelum diiradiasi dengan sinar gamma pada dosis 250 kGy. Penurunan ini terjadi karena adanya cacat struktur di dalam bahan komposit Fe-C akibat interaksi radiasi sinar gamma dengan bahan komposit Fe-C.
Analisis Penambahan Fe Terhadap Sifat Listrik Dan Magnet Komposit Mwcnt-Fe Purwanto, P.; Mustofa, Salim
Jurnal Kimia dan Kemasan Vol. 36 No. 2 Oktober 2014
Publisher : Balai Besar Kimia dan Kemasan

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Bahan komposit MWCNT-Fe dibuat dengan mencampurkan serbuk MWCNT dan Fe dengan variasi kandungan Fe mulai dari 1% sampai 5%. Selanjutnya bahan komposit diproses milling selama 3 jam memakai teknik High Energy Milling (HEM). Hasil pola difraksi sinar- x komposit MWCNT-Fe menunjukkan adanya puncak MWCNT dan Fe dengan pola yang sama. Spektroskopi Raman menunjukkan puncak D band muncul pada 1310- 1320 cm-1, puncak harmonik kedua G band (G’ band) muncul pada Raman shift 1605 cm-1 sampai dengan 1615 cm-1, dan puncak tangensial G band muncul pada 1580 cm-1 sampai dengan 1595 cm-1. Hasil pengukuran konduktivitas MWCNT-Fe dengan alat ukur LCR, menunjukkan bahwa nilai konduktivitas mengalami kenaikan sebanding dengan kenaikan berat Fe. Hasil parameter magnetik dengan metode VSM (Vibrating Sample Magnetometer) menunjukkan Magnetik Rimanen (Mr), Magnetik Jenuh (Ms) mengalami kenaikan, sedangkan Medan Koersif (Hc) mengalami penurunan sebanding dengan kenaikan berat Fe. 
STUDI PENDAHULUAN PEMBUATAN LAPISAN TIPIS MWCNT-Fe PADA PERMUKAAN GELASDENGAN SPIN COATING Purwanto, P.; Yunasfi, Yunasfi; Mustofa, Salim
Jurnal Sains Materi Indonesia Vol 17, No 1: OKTOBER 2015
Publisher : BATAN

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (402.481 KB) | DOI: 10.17146/jsmi.2015.17.1.4196

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STUDI PENDAHULUAN PEMBUATAN LAPISAN TIPIS MWCNT-Fe PADA PERMUKAAN GELASDENGAN SPIN COATING. Telah dilakukan pembuatan lapisan tipis Multi-Walled Carbon Nanotubes (MWCNT)-Fe pada permukaan gelas. Pengukuran struktur kristal campuran serbuk MWCNT-Fe dilakukan dengan XRD, dimana pola difraksi yang nampak menunjukkan adanya puncak dari carbon dan Fe saja, tidak ditemukan unsur pengotor lainnya. Pengamatanmorfologi denganmenggunakan SEM menunjukkan permukaan lapisan tipis MWCNT-Fe yang terbentuk pada permukaan substrat gelas. Pengukuran sifat listrik pada lapisan tipis MWCNT-Fe selanjutnya dilakukan untuk mengetahui efek perubahan frekuensi ukur terhadap nilai konduktansi dan kapasitansi. Secara umum nilai konduktansi relatif stabil terhadap perubahan frekuensi, sedangkan nilai kapasitansi lapisan tipis MWCNT-Fe mengalami penurunan seiring dengan naiknya frekuensi ukur. Namun seiring dengan bertambahnya persen (%) berat Fe di dalamlapisan tipis, nilai konduktansi lapisan tipis naik drastis, dan sebaliknya nilai kapasitansi mengalami penurunan drastis seiring dengan naiknya frekuensi pengukuran. Dari spektrum Raman terlihat adanya puncak D band pada posisi 1310 cm-1 hingga 1320 cm-1, puncak harmonik pertama G band (tangensial G band) pada posisi 1580 cm-1 hingga 1595 cm-1, dan puncak harmonik kedua G band (G’ band) pada posisi 1605 cm-1 hingga 1615 cm-1.
PREPARATION OFNb BASED THIN FILM USING PULSED LASER DEPOSITIONAND ITS ELECTRICAL PROPERTY Mustofa, Salim; Yusuf, Saeful
Jurnal Sains Materi Indonesia Vol 14, No 4: JULI 2013
Publisher : BATAN

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (167.377 KB) | DOI: 10.17146/jsmi.2013.14.4.4388

Abstract

PREPARATION OFNb BASED THIN FILM USING PULSED LASER DEPOSITIONAND ITS ELECTRICAL PROPERTY. The research for largering capacity of dielectric multi layer type capacitor using Pulsed Laser Deposition (PLD) method was carried out. In this study, we focus on the inexpensive material Nb as a substitute for expensive material Ta, which is currently used for ferroelectric material. The Nb-based (Nb2O5) and TiO2 particle were deposited on Si/SiO2 substrate at temperature of 600 oC under the oxygen pressure of 5Pa, and Pt was used as the last layer. Doping of TiO2 to the Nb2O5was carried out by alternately replacing each target and finally the deposited film with a thickness of 200 nm was achieved. The capacity value of pure Nb2O5 thin film was higher than pure TiO2 , but TiO2 was more stable against the changes of temperature. The capacitor that has a ratio of 30% Nb2O5 showed the highest capacity value. Single layer of Nb2O5 thin film has the largest rate of change in capacitance, and the capacitor that already doped by TiO2 has a more less changes in capacitance against the changes of temperature. In order to crystallize, the capacitor was then annealed in the air for 12 hours at the temperature of 700o . Same as before annealing, a mixed thin film thas has a ratio 30% of Nb2O5 still showed the highest capacity value, even there is a small changes against the against the changes of temperature. Other mixed thin film with different ratio of TiO2 have more stable temperature characteristics, but the capacity value was very small. From above results, it can be considered that the thin film of 30% of Nb2O5 and 70% of TiO2 is the best potential with highest capacity value and small changes against the changes of temperature.