• Heryanto, Heryanto

Abstract

<jats:p>Electronic equipment demand is strongly correlated to the electromagnetic wave interference (EMI), which causes severe effects on human health. Microwave absorbing materials (MAMs) are one method to protect human health from EMI. Cobalt nanoparticles show high performance as MAMs. Here, we have synthesized CoFeO<jats:sub>3</jats:sub> by simple mechanical alloying for increased multiple reflections, interfacial polarization, magnetic domain loss, electron spin loss, internal resonance, hoping electron, conductive loss, and multiple scattering for improved absorption of EMI waves. We determined the electronic properties from the Quantum Espresso (QE) and corresponding results are discussed. The metallic character comes from the d-state of transition metal atoms Fe (II) and Co which are sufficiently large in magnitude in the Fermi level of band structure and density of state (DOS) distribution. Crystallite size in the range of 13.6 to 18.7 nm with surface morphology shows irregular shapes of the particles. For CoFeO<jats:sub>3</jats:sub> as MAMs, we found that the reflection loss (RL) is −55 dB (lower than the previous reported −43.2 dB) at 10–11 GHz for a thickness of 8 mm, indicating that this study shows high potential of CoFeO<jats:sub>3</jats:sub> as an alternative composite for MAMs applications.</jats:p>

Topics

• nanoparticle
• density
• impedance spectroscopy
• surface
• composite
• cobalt
• band structure