Electronic and Optical Properties of Materials (Polymers, Conductor, and Oxide) by Analysis Quantitative X-ray Photoelectron Spectroscopy (XPS) and Reflection Electron Energy Loss Spectroscopy (REELS)

Program Academic Recharging (PAR)-C ini memberikan peluang dosen dari perguruan tinggi Indonesia untuk melakukan penelitian di universitas luar negeri. Program ini telah menghasilkan penelitian dan hasilnya 2 buah manuskrip yang telah di publikasi di Journal Internasional yaitu yaitu Journal of Applied Physics (JAP) dan Journal of Physics D: Condensed Matter. \ud Penelitian yang dilakukan difokuskan untuk menentukan sifat elektronik dan sifat optic dari polimer dan logam Cu dan oksidanya yang bersifat semikonduktor yaitu CuO dan CuO2. Polimer yang diteliti adalah polymethyl-methacrylate (PMMA), polyethylene (PE), polyvinyl chloride (PVC), polyester (PET), polypyrrole (PPY), and polyamide (PA6)

Search for the Heisenberg spin glass on rewired square lattices with antiferromagnetic interaction

Spin glass (SG) is a typical magnetic system with frozen random spin\ud orientation at low temperatures. The system exhibits rich physical properties,\ud such as infinite number of ground states, memory effect and aging phenomena. There are two main\ud ingredients considered to be pivotal for the existence of SG behavior,\ud namely, frustration and randomness. For the canonical SG system,\ud frustration is led by the presence of competing interaction between\ud ferromagnetic (FM) and antiferromagnetic (AF) couplings. Previously,\ud Bartolozzi {\it et al.} [ Phys. Rev. B{\bf 73}, 224419 (2006)],\ud reported the SG properties of the AF Ising spins on scale free network (SFN).\ud It is a new type of SG, different from the canonical\ud one which requires the presence of both FM and AF couplings.\ud In this new system, frustration is purely caused by the topological\ud factor and its randomness is related to the irregular connectvity.\ud Recently, Surungan {\it et. al.} reported SG bahavior of AF Heisenberg\ud model on SFN. We further investigate this type of system\ud by studying an AF Heisenberg model on rewired square lattices.\ud We used Replica Exchange algorithm of Monte Carlo Method and\ud calculated the SG order parameter to search for the existence of\ud SG phase

Pengembangan Alat Ukur Migrasi Klorida Pada Bahan Biomassa Dari Serbuk Gergaji Kayu Jati

Pada penelitian ini telah dibuat alat uji migrasi klorida dengan menggunakan pellet biomassa yang terbuat dari arang serbuk gergaji kayu jati putih sebagai bahan uji untuk menguji migrasi klorida pada alat uji migrasi klorida. Pembuatan alat uji migrasi klorida ini bertujuan untuk melihat hubungan antara arus dengan laju migrasi ion klorida pada bahan biomassa. Hasil pengujian alat uji migrasi klorida didapatkan bahwa semakin lama waktu yang dibutuhkan biomassa untuk dialiri ion klorida maka semakin besar pula arus yang digunakan untuk membuat ion klorida berdifusi ke dalam pori biomassa. Hal ini membuktikan bahwa alat uji migrasi klorida merupakan salah satu metode untuk membuktikan adanya migrasi klorida

Annealing Effect on Electronic Properties of Transparent Oxide Semiconductor Ga-In-Zn-O (GIZO) Thin Films

The effect of temperature annealing on electronic properties of Ga-In-Zn-O (GIZO) have been\ud studied quantitatively by use refelection electron energy loss spectroscopy (REELS), X-ray photoelectron\ud spectroscopy (XPS) and extended X-ray absorption fine structure (EXAFS) spectroscopy.\ud The bandgap value of GIZO were obtained as a function of temperature annealing from the\ud REELS spectra The band gap changes from 3.1 eV as deposited to 4.2 eV for annealing at 800oC.\ud The composition of element and chemical bonding in GIZO thin films were obtained by XPS and\ud EXAFS, respectively. The K-edge spectra by EXAFS were observed with sharp absorption edges\ud at 10.37 keV for Ga and 9.66 keV for Zn for GIZO thin films. The composition by XPS shows Ga\ud increase and Zn reduce while temperature annealing increase and will become GIO thin films for\ud 800oC. The composition changed as a function of temperature that impact to the electronic properties\ud of GIZO thin films are investigated

PENENTUAN SIFAT OPTIK DAN SURFACE EXCITATION PARAMETER (SEP) DARI FILM TIPIS ZINC OXIDE (ZNO) SEBAGAI WINDOW LAYER PADA SEL SURYA

The electronic and structural properties for RF magnetron sputtering deposited ZnO thin films grown on Si substrate was obtained by using X-ray diffraction (XRD) and reflection electron energy loss spectroscopy (REELS). XRD spectra show the intensity of the diffraction peak increases with increasing the growth temperature with (002) is strongest diffraction peak. The particle sizes for (002) are increase from 10.2 nm to 60.2 nm with increasing growth temperature from room temperature to 500oC, respectively. The band gap of ZnO thin films REELS spectra are 3.1???0.1 eV. The dominant peak from REELS at about 18 eV is ascribed to a bulk Plasmon excitation, which represents the collective oscillation of the valence electrons excited by the incident fast electrons

Radon (222Rn) Radioactivity Level at the BATAN Workplace using RAD7

Measurement of Radon (222Rn) radioactivity level at BATAN office Jakarta has been done. Radon is a radioactive emitting alpha particle, very dangerous to the health because if it is inhaled, will be accumulated in the lungs and cause lung cancer. The purpose of the research was to determine the activity concentration of 222Rn in the workplace and to estimate the dose received by workers. The sampling method is purposive sampling, in several office rooms of the BATAN office (staff room, laboratory, and warehouse), measurement 222Rn using RAD7 continuously for 24 hours. Based on the activity concentration of 222Rn in the rooms, an estimate of the effective dose received by the workers while working indoors can be calculated. The results showed that exposure of 222Rn gas radiation in the workplace was relatively varied, radiation exposure in warehouses was 18.90-32.90 (25.90) Bq.m-3 higher than in laboratory 8.20-34.00 (22.43) Bq.m-3 and staff room 5.40-29.60 (16.68) Bq.m-3. The estimated effective dose received by workers in the warehouse is 0.1865 mSv.year-1, laboratory 0.1615 mSv.year-1, and in the staff rooms 0.1267 mSv.year-1, and this value still meets the quality standards of radiation exposure required by the Ministry of Health No. 7 of 2019 and is categorized as safe

Sintesis dan Karakterisasi Fotoluminisens Carbon Dots Berbahan Dasar Organik dan Limbah Organik

Bahan dan limbah organik dapat disintesis menjadi CDs dengan metode green synthesis berbasis microwave assisted. Bahan organik yang digunakan adalah sawi, kentang, biji jagung dan limbah jagung (kulit dan tongkol jagung). Karakterisasi fotoluminisens (PL) digunakan untuk menunjukkan sifat optik CDs. Hasil karakterisasi PL dari CDs berbahan dasar bahan dan limbah organik menunjukkan panjang gelombang yang relatif sama yaitu 500 nm. Perbedaan CDs bahan dan limbah organik yaitu pada intensitas pendaran CDs. CDs biji jagung memiliki intensitas pendaran yang tinggi dibandingkan CDs yang berasal dari bahan organik lainya yaitu 42 a.u.. Sedangkan untuk limbah jagung memiliki panjang gelombang dan intensitas yang relatif sama. Besarnya energi gap yang dihasilkan dari CDs dari bahan organik berada disekitaran 2,46 eV, dimana berada pada rentang energi gap CDs. Hal ini menunjukkan bahwa bahan dan limbah organik dapat disintesis menjadi CDs dengan efektif, efisien, ekonomis dan ramah lingkungan

Stopping Powers and Inelastic Mean free Path of 100 eV to 30 keV Electrons in Zirconium Silicates

We have determined the electron stopping power (SP) and inelastic mean free path (IMFP) of (ZrO2)x(SiO2)1-x (x=1, 0.75, 0.5, 0.25, 0) for electron energy from 100 eV to 30 keV by means of modified Born???Ochkur equations. The energy loss function (ELF) required in the calculation of SP and IMFP. We have used the electron energy losses from 0 to 80 eV by quantitative analysis of reflection electron energy-loss spectroscopy (REELS) spectra. The value of SP and IMFP for high amount of ZrO2 (x=50% and x=75%) in Zr-silicates are similar to those of ZrO2 and for low amount of ZrO2 (x=25%) in Zr-silicates are similar to those of SiO2. There is small different value of SP and IMFP for ZrO2 and SiO2.We found that the SP decreases while IMFP increases with increasing the amount of electron energy. We have demonstrated the ELF from the quantitative analysis of REELS spectra provided us with a straight forward way to determine SP and IMFP for alloy materials by using modified Born-Ochkur equation

Studi Quality Control (QC) Pesawat Fluoroscopy (Angiografi) di PT. Siloam Internasional Hospital Makassar menggunakan Multimeter RaySafe (X2) dan Black Piranha RTI

Tujuan dari penelitian ini adalah melakukan uji quality control (QC) pada pesawat fluoroscopy (angiografi) di PT. Siloam Internasional Hospital Makassar, pengukuran didasarkan pada protokol QC yang dikembangkan oleh Radiological Council Western Australia. Pengukuran yang dilakukan meliputi akurasi tegangan tabung (kVp), waktu fluoroskopik maksimum, dan uji kualitas berkas/half value layer (HVL), linearitas keluaran (mGy/mAs), laju dosis permukaan II, dan kualitas citra. Hasil penelitian menunjukkan bahwa pengujian generator dan tabung pesawat sinar-x masih dalam batas toleransi yaitu 1,4%. Nilai maksimum laju dosis pasien tipikal 14,3 mGy/min, dan laju dosis serap reseptor citra sebesar 67,8 mGy/min untuk pengukuran menggunakan 20 cm phantom polymethyl methacrylate (PMMA) yang dioperasikan pada mode dosis normal dan dosis tinggi