PERTANIKA JOURNAL OF SCIENCE AND TECHNOLOGY

This research aims to test the characterisation of the barium ferrite copper nickel oxide (BaFe12-2xCuxNixO19) sample as a microwave absorbing material that will be applied to radio detection and ranging (Radar). The materials used in the synthesis process are barium carbonate (BaCO3), iron oxide (Fe3O4), copper sulfate (CuSO4), and nickel(II)chloride hexahydrate (NiCl2.6H2O) powders, while the solutions are 12 M hydrochloric acid (HCl), ammonium hydroxide (NH4OH), and distilled water, which has been synthesised using the coprecipitation method with varying ion doping x = 0.0, 0.4, 0.8, and 1.0%, which is calcined at temperatures of 200, 600, and 1,000°C. The samples were then tested for characteristics through four stages of testing, namely X-ray diffraction (XRD), Fourier transform independent infrared spectroscopy (FTIR), transmission electron microscope (TEM), vibrating sample magnetometre (VSM), and vector network analyser (VNA). The test results using FTIR produced peaks at wave numbers 584-1639 cm⁻¹, which indicated the presence of Ba-O, Fe-O, Cu-O, and Ni-O functional groups. This indicates that the materials used in the synthesis process reacted or were present in the final sample. The test results using TEM with a sample of x = 1.0% and a calcination temperature of 1,000°C show that the resulting particles are hexagonal with a size of 50 nm. Tests using VSM show that the low coercivity value decreases, and the magnetic remanence and magnetic saturation values ​​increase along with the use of ion doping and calcination temperature. The sample underwent a change from hard magnetic to soft magnetic based on the results of a decrease in the coercivity value and has the potential to become a microwave-absorbing material. The final test results using VNA produced a reflection loss value of -22.456 dB with an absorption percentage of 99.62%. The maximum electrical conductivity produced is 1.20305 at a temperature of 1,000°C. According to the indicators, the sample meets the criteria to be applied as a microwave-absorbing material, namely having a nanoparticle size, being soft magnetic, and being included as a semiconductor material.