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Material Absorber Gelombang Elektromagnetik Berbasis (La0.8Ba0.2)(Mn(1-x)/2ZnxFe(1-x)/2)O3(x = 0 – 0,6) Intan Wandira; Pulung Karo Karo; Wisnu Ari Adi
Jurnal Teori dan Aplikasi Fisika Vol 6, No 1 (2018): Jurnal Teori dan Aplikasi Fisika
Publisher : Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jtaf.v6i1.1827

Abstract

Electromagnetic wave absorber materials with(La0.8Ba0.2)(Mn(1-x)/2ZnxFe(1-x)/2)O3(x = 0-0,6) had been researched. This magnetic material was synthesized by using solid state reaction method and a suitable composition for the application of a microwave absorber material had been obtained, namely (La0.8Ba0.2)(Mn0.4Zn0.2Fe0.4)O3 (x = 0,2).Precursors use wereLa2O3, BaCO3, ZnO, Fe2O3, dan MnCO3. The mixture was mixed with High Energy Milling for 5 hours then sintered at 1000 ° C for 5 hours.The result of refinement of X-ray diffraction pattern shows that (La0.8Ba0.2)(Mn0.4Zn0.2Fe0.4)O3material had a single phase and a trigonal structure. The surface morphology of the sample had a uniform spherical shape. The results of absorbance analysis of samples to electromagnetic waves in the range of 8-12 GHz was 96%. Thus, the (La0.8Ba0.2)(Mn0.4Zn0.2Fe0.4)O3 (x = 0,2) material was a potential candidate for applications of electromagnetic wave absorber material.
Synthesis and Characterization of Ba0.6Sr0.4Fe12O19/LaMnO3 Composites as Microwave Absorbers Yohanes Edi Gunanto; Maya Puspitasari Izaak; Henni Sitompul; Wisnu Ari Adi
Indonesian Journal of Electrical Engineering and Informatics (IJEEI) Vol 9, No 4: December 2021
Publisher : IAES Indonesian Section

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.52549/ijeei.v9i4.3239

Abstract

The synthesis and characterization of Ba0.6Sr0.4Fe12O19/LaMnO3 composite material has been successfully carried out by mechanical alloying method using high energy milling. Crystal structure and surface morphology were characterized using x-ray diffraction and scanning electron microscopy. While the value of magnetization and the ability to absorb microwaves, vibrating sample magnetization and vector network analyzing were used, respectively. With variations in weight, does not change the crystal structure. The Ba0.6Sr0.4Fe12O19phase has a hexagonal structure and the LaMnO3 phase has an orthorhombic structure. Surface morphology has a heterogeneous size in the range of 200-450 nm with the form of platelets. The composite material Ba0.6Sr0.4Fe12O19/LaMnO3 is a hard-soft magnetic material with a magnetic saturation of Ms ~ 46.83 emu/g, Mr ~ 28.8 emu/g, and a coercive field of Hc ~ 3.88 kOe. The minimum reflection loss value is – 13.0 dB at 11.2 GHz frequency and 1.52 GHz bandwidth.
PEMBENTUKAN NANOPARTIKEL PADUAN CoCrMo DENGAN METODA PEMADUAN MEKANIK[Manufacturing of Co-Cr-Mo Alloy Nano-Particle by Using Mechanical Alloying]] Sulistioso Giat Sukaryo; Wisnu Ari Adi
Metalurgi Vol 27, No 1 (2012): Metalurgi Vol. 27 No. 1 April 2012
Publisher : National Research and Innovation Agency (BRIN)

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (929.07 KB) | DOI: 10.14203/metalurgi.v27i1.139

Abstract

AbstrakMetoda pemaduan mekanik adalah reaksi padatan dari beberapa logam dengan memanfaatkan proses deformasi untuk membentuk suatu paduan. Pada penelitian ini dibuat paduan Co-Cr-Mo dengan  proses wet milling dengan variasi waktu milling selama 3, 5, 10, 20, dan 30 jam. Proses wet milling sangat efektif untuk mencegah terjadinya oksidasi dan juga memicu pembentukan paduan Co-Cr-Mo dengan baik. Hasil XRD menunjukkan bahwa telah terjadi pertumbuhan fasa γ pada durasi milling 3, 5, 10, 20, dan 30 jam, berturut-turut sebesar 42,80 %; 67,61 %; 82,94 %, 84,63 % dan 88,92 %. Ukuran kristalit fasa γ sebesar 25,9 nm; 12,5 nm; 5,1 nm dan 4,9 nm seiring dengan meningkatnya waktu milling. Disimpulkan bahwa telah berhasil dilakukan pembuatan paduan nanokristalin Co-Cr-Mo dengan metode pemaduan mekanik lebih dari 85 % dengan waktu milling minimum selama 30 jam. Kata kunci : Co-Cr-Mo, pemaduan mekanik, nano-kristalin AbstractSynthesis of Co-Cr-Mo nano-crystalline by mechanical alloying has been carried out. Mechanical alloying is a solid state reaction of some metals by utilizing the deformation process to form an alloy. In this research, parameter milling time used for making Co-Cr-Mo alloy by wet milling process is 3, 5, 10, 20 and 30 h. Wet milling process is very effective to prevent oxidation and triggers the formation of fine Co-Cr-Mo alloys. Results of XRD pattern refinement shows that Co-Cr-Mo alloys was growth by percentage approximately around 42.80%, 67.61%, 82.94%, 84.63% and 88.92% for milling time 3, 5, 10, 20, and 30 h, respectively. Otherwise, crystalline size measurement after milling time 5, 10, 20, and 30 h obtained around 25.9 nm, 12.5 nm, 5.1 nm and 4.9 nm, respectively. This research concluded that the optimum milling time could obtained synthesizes nano-crystalline of Co-Cr-Mo alloy more than 85% is 30 h. Keywords: Co-Cr-Mo alloy, mechanical alloying,  nano-crystalline