Synthesis and Characterization Barium M-Hexaferrites (BaFe<sub>12-2x</sub>Co<sub>x</sub>Mn<sub>x</sub>Ni<sub>x</sub>O<sub>19</sub>) as a Microwave Absorbent Material

Abstract

This study aims to synthesize microwave absorbent material from barium M-Hexaferrite doped Co-Mn-Ni ions (BaFe12-2xCoxMnxNixO19) using co-precipitation method with varying concentrations (x = 0.2, 0.4, 0.6, 0.8, and 1.0) and calcinations temperatures in the range of 200 to 800°C. The samples characterization was conducted to investigate the effect of doping concentration variations on the electrical, magnetic and microwave absorption properties using X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM-EDX), Transmission Electron Microscope (TEM), Vibrating Sample Magnetometer (VSM), and Network Vector Analyzer (VNA). The results from XRD characterization showed that the sample formed the barium iron oxide (BaFe12O19) phase with a = b = 5.03Å and c = 13.43Å. The results of SEM-EDX and TEM samples of BaFe9.6Co0.8Mn0.8Ni0.8O19 showed that the sample size ranged from 79-165 nm in the hexagonal crystal structure form. The magnetic properties with VSM indicate that the sample coercivity value decreases significantly from 0.41 T at x = 0.0 to 0.09 T at x = 0.8, indicating that the sample is soft magnetic. The value of electrical conductivity is in the range of 2.42 x 10-4 to 9.30 x 10-4 S/cm shows that the sample is a semiconductor. Analysis of the absorption properties of microwaves with VNA produced maximum permittivity and permeability values ​​of 28.40 and 54.40 at 10.30 GHz, and a maximum Reflection Loss (RL) value of -20.20 dB at a frequency of 15 GHz with an absorption coefficient of 99.05 % at concentration x = 0.6. The high permittivity, permeability, RL, and absorption coefficients indicate that the BaFe12-2xCoxMnxNixO19 sample has the potential to be a microwave absorbent material on X-band to Ku-band frequency.