Synthesis of Magnetite Fe₃O₄from Laterite Iron Rock as Microwave Absorber Material

Synthesis of magnetite from laterite iron rock material was successfully introduced as microwave absorber material. In this research, magnetite has been made from laterite iron rock, Tanah Laut, South Kalimantan, Indonesia to be laterite iron sand was achieved by a simple method. Magnetite with paint coating is applied to steel grade A type AH36. The sample was characterized by an X-ray fluorescence spectrometer (XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM), and vibrating sample magnetometer (VSM) to investigated element composition, crystal structure, the morphology of particles, hysteresis loops of the magnetic sample, respectively. Based on the experiment, the magnetic particle properties have saturated magnetization of 120 emu g-1 and the coercive force of 0.05 T. VNA to investigate the absorption characteristics of microwaves in a frequency range between 8-12 GHz. The results showed that the reflection loss of magnetite is higher than uncoated steel samples. The sample has a maximum reflection loss value of -14.4 dB at 8 GHz with a sample thickness of 4 mm.