Article Per Year (5 Year)
p-Index From 2020 - 2025
0
P-Index
This Author published in this journals
All Journal Metalurgi
E Sukirman
Pusat Teknologi Bahan Industri Nuklir - BATAN
Energy

Published : 2 Documents Claim Missing Document
Claim Missing Document
Check
Articles

Found 2 Documents
Search

 1 
PENGARUH PENAMBAHAN KARBON AKTIF PADA STRUKTUR KRISTAL DAN MAGNETISASI PARTIKEL NANO Fe3O4[Addition Effect of Active Carbon on Crystal Structure and Magnetization of Fe3O4 Nanoparticles] Wardiyati, Siti; Sukirman, E
Metalurgi Vol 28, No 1 (2013): Metalurgi Vol.28 No.1 April 2013
Publisher : Pusat Penelitian Metalurgi dan Material - LIPI

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (357.785 KB) | DOI: 10.14203/metalurgi.v28i1.241

Abstract

PENGARUH PENAMBAHAN KARBON AKTIF PADA STRUKTUR KRISTAL DAN MAGNETISASIPARTIKEL NANO Fe3O4. Pengaruh penambahan karbon aktif (C) pada struktur kristal dan magnetisasipartikel nano Fe3O4 sebagai bahan adsorben telah diteliti. Cuplikan partikel nano Fe3O4 disintesis denganmetoda ko-presipitasi. Disiapkan cuplikan Fe3O4 murni (FeM) dan cuplikan Fe3O4 dengan penambahan C,dimana perbandingan berat prekursor Fe3O4 terhadap C divariasiakan. Variasi perbandingan berat Fe3O4terhadap C adalah 1:1, 1:2 dan 1:3, selanjutnya cuplikan disebut berturut-turut FeC11, FeC12 dan FeC13.Cuplikan dikarakterisasi dengan XRD (x-ray diffraction), VSM (vibrating sample magnetometer) dan TEM(transmission electron microscope). Hasil analisis data difraksi sinar-x dengan metoda Rietveld menunjukkanbahwa parameter kisi Fe3O4 pada FeM, FeC11, FeC12 dan FeC13 berturut-turut adalah a = b = c = 8,390(3) Å; a= b = c = 8,433(4) Å; a = b = c = 8,43(1) Å dan a = b = c = 8,434(5) Å. Kurva magnetisasi dari FeM, FeC11,FeC12 dan FeC13 masing-masing menampilkan sifat superparamagnetik. Harga magnetisasi, Ms cuplikan FeM,FeC11, FeC12 dan FeC13 berturut-turut adalah 60, 30, 20 dan 15 emu/g. Semakin banyak C ditambahkan,parameter kisi Fe3O4 bertambah panjang. Ini berarti sebagian C masuk ke dalam sistem kristal Fe3O4 secarainterstisi. Semakin banyak atom C di posisi interstisi antara Fe dan Fe, harga magnetisasi Fe3O4 terus menyusut.Cuplikan FeC12 memiliki ukuran kristalit magnetite terkecil atau luas permukaan yang paling besar. Sehinggamemungkinkan memiliki kapasitas adsorpsi yang paling besar. abstractThe addition effect of Carbon active (C) on crystal structure and magnetization of Fe3O4 nanoparticles asadsorbent have been studied. The samples of Fe3O4 nanoparticles have been synthesized by coprecipitationmethod. It were prepared Fe3O4 samples without and with the addition of C. The sample without C addition iscalled FeM, and the weight ratio of Fe3O4 precursors to C were varied. The Fe3O4 weight ratio to C is 1:1, 1:2and 1:3, hereinafter called FeC11, FeC12 and FeC13, respectively. The samples were characterized by XRD(x-ray diffraction), VSM (vibrating sample magnetometer) and TEM (transmission electron microscope). Theanalysis results of x-ray diffraction data using the Rietveld method showed that the lattice parameters ofFe3O4 on FEM, FeC11, FeC12 and FeC13 are as follows: a = b = c = 8.390 (3) Å, a = b = c = 8.433 (4) Å, a= b = c = 8.43 (1) Å, and a = b = c = 8.434 (5) Å, respectively. Each magnetization curves of the FEM,FeC11, FeC12 and FeC13 show the super paramagnetic properties. The magnetization of FEM, FeC11,FeC12 and FeC13 are Ms = 60, 30, 20 and 15 emu/g, respectively. The more C added, the longer the Fe3O4lattice parameter is. This means that some C entered into the crystal system of Fe3O4 as interstitial atoms.With growing number of C atoms in the interstitial positions between Fe and Fe, magnetization of Fe3O4decreases. FeC12 sample has the smallest size of crystallites or the large surface area. So it may have thegreatest adsorption capacity.
SIFAT LISTRIK SUPERKONDUKTOR YBa2Cu3O7-x HASIL PROSES PELELEHAN DENGAN DOPANT Ti[Electrical Characterictic of YBa2Cu3O7-x Superconductor Doped by Ti Using Melting Process] Winataputra, Didin S; MP, Yustinus; AA, Wisnu; Deswita, Deswita; Sukirman, E
Metalurgi Vol 27, No 1 (2012): Metalurgi Vol. 27 No. 1 April 2012
Publisher : Pusat Penelitian Metalurgi dan Material - LIPI

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (632.68 KB) | DOI: 10.14203/metalurgi.v27i1.137

Abstract

 SIFAT   LISTRIK   SUPERKONDUKTOR  YBa2Cu3O7-x    HASIL PROSES   PELELEHAN   DENGANDOPANT Ti. Telah dilakukan pembuatan superkonduktor YBa2Cu3O7-x  (YBCO) yang didoping Ti melaluiproses modified melt textured growth (MMTG). Pembuatan cuplikan dilakukan melalui reaksi padatan dengancara menambahkan serbuk Ti ke dalam prekursor YBCO dengan variasi komposisi 0,4 % berat, 0,7 % berat, 1,0% berat dan 1,3 % berat. Proses pelelehan YBCO dilakukan pada 1100 °C selama 12 menit, kemudian didinginkan dengan cepat ke 1000 °C dan diikuti dengan pendinginan lambat ke 960 °C. Identifikasi fasa di dalam cuplikan dilakukan dengan menganalisis pola difraksi sinar-X dengan metode Rietveld. Rapat arus, Jc dan suhu kritis, Tc diukur menggunakan four point probe (FPP). Struktur mikro dan komposisi fasa cuplikan diamati dengan scanning electron microscope (SEM) dan energy dispersive x-ray spectroscopy (EDS). Hasil pengamatan menunjukkan bahwa cuplikan merupakan bahan superkonduktor Tc tinggi (STT). YBa2Cu3O7-x/Ti - fasa 123 berstruktur kristal ortorombik dari grup ruang Pmmm no. 47. Rapat arus kritis, Jc cuplikan Y-0Ti diperoleh sekitar 67 A.cm-2     dan   kemudian    turun    terus dengan    kenaikan      prosentase    doping     Ti      hingga Jc » 4 A.cm-2. Menyusutnya harga Jc disebabkan Ti tidak dapat mencegah pertumbuhan fasa 211. Bila kandungan Ti bertambah, fasa 211 juga bertambah dengan distribusi tidak homogen dan tumbuh terus serta terbentuk retakan mikro yang sejajar dan memotong butiran YBCO. Akibatnya, fasa YBCO berukuran lebih pendek dan kecil dibandingkan fasa YBCO tanpa doping Ti. Demikian juga, dengan bertambahnya kandungan Ti menyebabkan suhu kritis (Tc) berkurang dari 365 °C menjadi  350 °C. AbstractELECTRICAL  CHARACTERICTIC  OF  YBa2Cu3O7-x     SUPERCONDUCTOR  DOPED  BY  Ti  USINGMELTING  PROCESS.  Synthesis  of  YBa2Cu3O7-x  (YBCO) superconductor  which  is  doped  by  Ti  usingmodified melt-textured growth (MMTG) method has been done. The specimen was made by solid state reaction by adding Ti powder to precursor of YBCO result with composition variation (in weight %) of 0.4, 0.7, 1 and1.3. The melt process of YBCO was done at 1100°C for 12 minutes then cooled rapidly to 1000°C followed by slow cooling to 960°C. Identification of the specimen phase was verified using x-rays diffraction (XRD) and followed by Rietveld method analysis. The critical temperature, Tc and current density, Jc were measured by means of four point probe (FPP). The microstructure and chemical composition of the specimen were observedusing scanning electron microscope (SEM) and energy dispersive x-ray spectroscopy (EDS). The result shows that the specimen was YBa2Cu3O7-x high Tc superconductor of 123-phase having orthorhombic crystal structure of Pmmm no. 47 space group. The critical current density, Jc of the specimen was obtained about 67A.cm-2 and then decreased continuously with increasing of Ti dopant till Jc » 4A.cm-2. Decreasing of Jc caused by Ti cannot prevent the growth of 211 phases. In increasing Ti content, 211 phases also increase with unhomogeneousdistribution and continue to grow. There is also formation ofmicrocracks parallel to and crossing the YBCO grains. As a result, YBCO have smaller and shorter grain size compared to YBCO grain without Ti doping. Increasing of Ti content also cause decrease from 365 °C to 350 °C.
Co-Authors AA, Wisnu Deswita Deswita MP, Yustinus Siti Wardiyati Winataputra, Didin S