Effect of Surfactant Concentration, Replacement Tip Height, Pulse On Off Times, and Dispersant Media on BaFe10.8Mg0.6Al0.6O19 as a Radar Absorber Material
Erlina Yustanti1,2a), Alfian Noviyanto3,4 b), Ahmad Taufiq5,c), Tubagus Maulana Ikhsan1,d), Laila Chusnul Chotimah1,e) and Maulana Randa6,f)

1Department of Metallurgical Engineering, Faculty of Engineering, Sultan Ageng Tirtayasa University
Jl. Jend. Sudirman KM. 03 Cilegon, Banten 42435, Indonesia
2Centre of Excellence, Nanomaterial and Process Technology Laboratory,
Faculty of Engineering, Sultan Ageng Tirtayasa University
3Advanced Materials Research Group, Nano Center Indonesia, Jl. PUSPITEK, Tangerang Selatan,
Banten, 15314, Indonesia
4Department of Mechanical Engineering, Mercu Buana University
Jl. Meruya Selatan, Kebun Jeruk, Jakarta 11650, Indonesia
5Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Negeri Malang
Jl. Semarang No 5, Malang 65145, Indonesia
6Research and Development Agency, Indonesia Ministry of Defense.
Jl. Jati No.1, Pondok Labu, Jakarta 12450 Indonesia

Abstract

Radar Absorbing Materials as microwave absorbing materials are very interesting to continue to be developed by researchers. Efforts to increase the absorption of electromagnetic waves with a low production cost with a large production scale are the main attractions for researchers. Material engineering with the substitution of Mg-Al in barium hexaferrite through the mechanical alloying process which can change the properties of the material from hard magnet to soft magnet is very attractive because it is practical and environmentally friendly. The increase in absorption of electromagnetic waves is influenced by particle sizes, in which the smaller the particle sizes, the greater the contact surface area between particles will be. The 20-kHz high-power ultrasonic destruction method effectively reduces the particle sizes so it results in a homogeneous distribution by controlling the parameters in the sonication technique. In this study, the synthesis of absorbing material began with mixing stoichiometric precursors of BaCO3, Fe2O3, MgO, and Al2O3 in a planetary ball mill. The mechanical alloying process using an alcohol medium at a speed of 3000 rotations per minute for 20 hours resulted in homogenization and amorphization. Sintering at a temperature of 1200oC for 2 hours succeeded in growing BaFe10.8Mg0.6Al0.6O19 crystallite embryos. Sonication for 6 hours at an amplitude of 55% succeeded in reducing the particle size of BaFe10.8Mg0.6Al0.6O19 to 90.5%. The optimal parameters in the sonication process were surfactant concentration of 0.01%, replacement tip height of 2 cm, and pulse on-off of 59:59 seconds in ethanol dispersant media, which resulted in 51-nm BaFe10.8Mg0.6Al0.6O19 nanoparticles. The nanoparticle resulting from the sonication technique at the optimum parameters succeeded in reducing the reflection loss by -31.636 dB and increasing the absorption of electromagnetic waves by 99.92% at a frequency of 8.2-12.4 GHz.

Keywords: Barium hexaferrite, reflection loss, radar absorbing material, ultrasonic irradiation

Topic: Magnetic materials