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PENGARUH ADITIF BaCO3 PADA KRISTALINITAS DAN SUSEPTIBILITAS BARIUM FERIT DENGAN METODA METALURGI SERBUK ISOTROPIK Nugraha, Priska R.; Widanarto, Wahyu; Cahyanto, Wahyu Tri; Kuncoro, Handoko S.
BERKALA FISIKA 2015: Berkala Fisika Vol. 18 No. 1 Tahun 2015
Publisher : BERKALA FISIKA

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (434.367 KB)

Abstract

Influences of concentration of BaCO3 on crystallinities and susceptibilities of barium ferrites using isotropic powder metallurgy method of fabrication is studied based on the characterization of X-Ray Diffraction (XRD), crystallite size distributions and hysteresis curve of Vibrating Sample Magnetometer (VSM).  In this study, Fe2O3 of Cilacap iron sands are doped with BaCO3 with various concentrations of 15%, 30% and 45% at 1100 °C of sintering temperature.  The results show that the addition of BaCO3 affects the formation of the multi-phase barium ferrite crystals and widen the crystallite size distribution, as well as lowering the saturations and the magnetic remanences. The optimum composition for barium ferrite magnets is obtained for 15% of BaCO3, with the highest mass susceptibility of 2.4 × 10-6 M3/Kg. Keywords: Barium hexaferrites, isotropic powder metallurgy, crystal characterizations, permanent magnets
PENINGKATAN SIFAT MAGNETIK MATERIAL HEMATIT MELALUI SUBTITUSI BARIUM DAN KONTROL TEMPERATUR SINTERING Widanarto, Wahyu; Fauzi, Fuzi Nurrahman; Cahyanto, Wahyu Tri; Effendi, Mukhtar
BERKALA FISIKA 2015: Berkala Fisika Vol. 18 No. 4 Tahun 2015
Publisher : BERKALA FISIKA

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Abstract

Ferrite magnet or ceramic magnet is a competitive product in the magnet market due to low price, corrosion resistant and chemically stable. Barium hexa-ferrite magnet is one of ferrite magnet which is mostly used as magnetic storage and electronic devices based on nanotechnology. Barium hexa- ferrites are synthetized through solid state reaction method at sintering temperatures of 1100 °C with the composition (100-x)Fe2O3 : xBaCO3 , where x = 0 and 20 in mol % . Results of XRD characterization show that the diffraction peaks of XRD spectrum is dominated by the peaks of barium ferrite crystal with a hexagonal crystal system. Magnetic properties of Fe2O3 material doped with barium carbonate of 20 mol % and sintered at 1100 °C increase significantly compared to the others. This simple and inexpensive method is very promising for the manufacture of barium hexa-ferrite materials with natural ferrite as the main material.Keywords: Iron sand, barium ferrite, structure, magnetic properties
Enhanced Microwave Absorption Quality of Bio-Silica-Barium-Ferrite Composites: Interplay of Fe3+ and Si4+ Widanarto, Wahyu; Effendi, Mukhtar; Cahyanto, Wahyu Tri; Ghoshal, Sib Krishna; Kurniawan, Candra; Handoko, Erfan; Alaydrus, Mudrik
Molekul Vol 18 No 2 (2023)
Publisher : Universitas Jenderal Soedirman

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20884/1.jm.2023.18.2.7326

Abstract

This paper reports the improved microwave (MW) absorption characteristics of some newly prepared bio-silica-barium-ferrite composites (SBFCs) of the form (x)Bio-SiO2:(80-x)Fe2O3:(20) BaO (where x = 0, 2, and 4 wt.%). These composites were prepared using the modified solid-state reaction method with simultaneous sintering at 800 and 1100 °C. SBFCs were studied to determine the impact of various bio-silica concentrations on their morphology, structure, magnetic properties, permittivity, permeability, and X-band reflection loss. Various SBFC thicknesses were simulated to determine the reflection loss curves. It has been established that the MW absorption capacity of the examined SBFCs may be altered by adjusting the bio-silica concentration and sample thickness.
STUDI KOMPARATIF ARANG AKTIF LIMBAH BIOMASSA SEBAGAI RADAR ABSORBING MATERIAL (RAM) Nisa, Dinda Khoirun; Ruyat, Yayat; Hafizah, Mas Ayu Elita; Widanarto, Wahyu
Jurnal Fisika : Fisika Sains dan Aplikasinya Vol 9 No 2 (2024): Jurnal Fisika : Fisika Sains dan Aplikasinya
Publisher : Universitas Nusa Cendana

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35508/fisa.v9i2.19340

Abstract

Stealth technology (teknologi siluman) merupakan salah satu teknologi yang sedang dikembangkan untuk menghilangkan jejak RADAR dari musuh. Spektrum yang digunakan dalam teknologi ini yaitu pada rentang gelombang mikro (8 – 12 GHz). RAM (Radar Absorbing Material) merupakan salah satu rekayasa yang dapat digunakan dalam perancangan teknologi siluman. Salah satu bahan yang berpotensi untuk dijadikan RAM adalah arang aktif sebagai bahan dielektrik. Dalam tulisan ini dilakukan studi komparatif terkait arang aktif dari beragam limbah biomassa, seperti jerami gandum, sekam padi, sekam, loofah, ampas tebu, kulit jeruk bali, kulit nangka, batok kelapa, dan semangka. Tiap arang aktif dari bahan baku berbeda akan mendapatkan nilai frekuensi dan daya serap yang berbeda. Sekam padi dan loofah merupakan limbah biomassa yang berpotensi untuk dijadikan sebagai RAM karena memiliki daya serap yang baik dan frekuensi yang sesuai dengan teknologi siluman ini.
Design of mobile application for communication and user interface of ESP32 potentiostat system Supriyanti, Retno; Widanarto, Wahyu; Dwi Susanto, Putra; Ardi Wicaksono, Madya; Rais Akhdan, Syafrudin; Alqaaf, Muhammad
International Journal of Reconfigurable and Embedded Systems (IJRES) Vol 14, No 3: November 2025
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/ijres.v14.i3.pp725-733

Abstract

The potentiostat utilizing the ESP32 has a 12-bit analog-to-digital converter (ADC), meaning the maximum value for ADC voltage readings on the ESP32 is 4095. These ADC readings are then converted into actual voltage units, ensuring more accurate measurements on the potentiostat. To facilitate the use of the ESP32 potentiostat, a mobile application must be designed as a user interface for data communication. The application will be developed on a mobile platform using a Bluetooth low energy (BLE) communication channel for easier access. The development process will utilize visual studio code as the code editor and programming languages like Dart and Flutter. The resulting application will feature a user-friendly dashboard, display data in a cyclic voltammetry graph, and store data in comma-separated values (CSV) files or images in the phone’s memory. This stored data will simplify observing results obtained from the ESP32 potentiostat.
Enhanced Microwave Absorbing Characteristics of Cerium Barium Ferrite Composite: Effect of Sintering Temperature Variation Widanarto, Wahyu; Tamtowi, Tomy; Effendi, Mukhtar; Rahmawati, Dina; Supriyanti, Retno; Ghoshal, Sib Krishna; Kurniawan, Candra; Jatmika, Jumaeda; Handoko, Erfan; Umar, Lazuardi; Alaydrus, Mudrik
Molekul Vol 20 No 3 (2025)
Publisher : Universitas Jenderal Soedirman

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20884/1.jm.2025.20.3.17825

Abstract

ABSTRACT. Cerium barium ferrite composites (CeBFCs) with improved microwave absorbance in the X-band spectral region are advantageous for varied advanced applications. Thus, the influence of various sintering temperatures on the microwave-absorbing traits of CeBFCs was evaluated. The main objective was to enhance the selective microwave absorption of BFC by modifying its magnetic properties through the substitution of Fe³⁺ with Ce³⁺ in the lattice structures. Four composites of CeBF were synthesized via mechanical alloying and sintered at 600, 800, 1000, and 1100°C. The produced samples were analyzed using XRD, VSM, and VNA to determine their microstructures, magnetic properties, and microwave reflection loss at X-band frequencies. XRD results revealed a significant promotion in forming a more pure crystalline barium hexaferrite phase at sintering temperatures higher than 800°C. This structural enhancement could directly influence the magnetic properties of the specimens with a progressive increase in the saturation magnetization with rising sintering temperature. In addition, the sintering temperature variation effectively modulated the electromagnetic properties (complex relative permeability and permittivity) that are vital for impedance matching and optimal wave absorption. The composite sintered at 1000°C displayed an optimal microwave absorption, indicating the lowest reflection loss within the X-band. The obtained products were shown to attenuate and dissipate surplus electromagnetic energy within the 8-12 GHz frequency range. The observed superior performance of the composites was ascribed to a balanced interplay between the magnetic and dielectric losses, leading to efficient impedance matching. It was affirmed that careful tuning of the sintering temperature can improve the crystalline phases, magnetic, electromagnetic, and microwave absorption properties of the proposed CeBFCs. Keywords: Cerium barium ferrite, Microwave absorption, Reflection loss, Sintering temperature, X-band