Magnetic Nanocomposite for Potential Ultrahigh Frequency Microelectronic Application

Abstract

Cobalt ferrite nanocomposites were investigated as example materials for microelectronic applications in the ultrahigh frequency range. Both static magnetic properties (magnetization versus applied field curve) and dynamic properties (complex permeability and permittivity at frequencies up to 1 GHz) were studied. When the ferritic density reached a certain level, the coercivity of the composite material decreased and the permeability increased noticeably. This phenomenon indicated the establishment of magnetic coupling between particles, which is necessary for magnetic nanocomposites to be used in electronic applications. Compared to magnetic composites made of micronsized fillers, the magnetic loss of the nanocomposites was lower. However, the permeability of the nanocomposite was also lower. Cobalt zinc ferrite nanocomposites were prepared to explore the effect of composition, which revealed that the permeability of the magnetic nanocomposite could be improved by modifying the composition.

In situ Production of Polystyrene Magnetic Nanocomposites through a Batch Suspension Polymerization Process

“…Magnetic particles are extensively used for the immobilization of biological protein and enzyme, enzyme‐linked immunosorbent assays, magnetizable implants for targeted drug delivery, immunomagnetic separations, nanoprobes for biomedical imaging in vivo, environmental and analysis, stimuli‐responsive systems, magnetic recording, catalysis, ultrahigh frequency microelectronic application, magnetic refrigeration, electromagnetic wave absorbers, contrast agents in magnetic resonance imaging, and hyperthermia agents 4–13…”

“…Several kinds of magnetic nanoparticles presenting different magnetic metals can be used for magnetic purposes, as for instance, magnetite (Fe3O4), maghemite (γ‐Fe 2 O 3 ), iron cobalt oxide (CoFe 2 O 4 ), cobalt zinc ferrite (Co 0.5 Zn 0.5 Fe 2 O 4 ), barium ferrite (BaFe 12 O 19 ), MnZn ferrite, NiZn ferrite, strontium ferrite (SrFe 12 O 19 ), Zn 0.6 Cu 0.4 Cr 0.5 Fe 1.5– x La x O 4 ($0\leq x\leq 0.06$ ) ferrites, and manganese perovskite La 1– x Sr x MnO 3 ($0.2\leq x\leq 0.3$ ) 9–11, 14–21. In spite of the large number of magnetic nanoparticles, special attention is given to superparamagnetic magnetite (Fe 3 O 4 ) nanoparticles due to its remarkable features, such as biocompatibility, low toxicity, low susceptibility to changes due to oxidation, magnetic retention only when exposed to an external magnetic field and strong ferromagnetic behavior 22–25…”

Localized Therapeutic Approaches Based on Micro/Nanofibers for Cancer Treatment

“…As described so far, the fibers have a potential application for local drug delivery. Their combination with MNPs may further increase their interest for cancer treatment [ 92 ]. Below are described several drug delivery systems using MNPs combined with fibers.…”

A Technology Overview of the PowerChip Development Program

“…Magnetic nanoparticles are attractive candidates to be used in inductor cores [82], [83]. Below the critical size, magnetic nanoparticles have a single magnetic domain and become superparamagnetic with zero coercivity at room temperature.…”