Appearance of ferromagnetism property for Si nano-polycrystalline body and vanishing of electrical resistances at local high frequencies

TL;DR

This study investigates the unique ferromagnetic and electrical properties of sintered Si nanopolycrystalline bodies at high frequencies, revealing phenomena like near-zero resistance and negative resistance, with potential applications in electronics.

Contribution

It demonstrates ferromagnetism in sintered Si nanopolycrystalline bodies and explains the vanishing resistivity at MHz frequencies through numerical modeling.

Findings

Vanishing electrical resistance near MHz frequencies

Observation of ferromagnetism in Si nanopolycrystalline

Negative resistance phenomena at high frequencies

Abstract

Reduction in the skin effect for the sintered Si nanopolycrystalline body as an electricity conductor at a high frequency due to its nano-structure was studied. Singular vanishing of electrical resistances near a local high magnetic harmonic frequency of a few MHz was observed. This phenomenon has not been observed for conventional ferromagnetic metals. The measured electrical resistances changed to almost 0 m{\Omega} at room temperature. At the same time, negative resistance of the sintered Si nano-polycrystalline body was observed. It will be applicable to electronic transmittance lines or semiconductors. Numerical calculation was also performed on the electrical resistance with frequency dependency while considering the electric field and magnetic field in the sintered Si nanopolycrystalline body. The calculation could explain the variation of the relative permittivity of the Si nanopolycrystalline and the phenomenon for vanishing the resistivity at frequency of MHz theoretically. Reduced Si nanoparticles from SiO2 powder were synthesized by laser ablation in liquid. A Si nano-polycrystalline body made of the reduced Si nanoparticles was fabricated. It was found by measuring the magnetization property of the body that the sintered Si nano-polycrystalline body has ferromagnetism. High-density dangling bonds cause the sintered Si nanopolycrystalline to have ferromagnetism. In this study, the density of the unpaired electrons in the sintered Si nanopolycrystalline was observed using ESR. It has been clarified that the Si nanopowder and the sintered Si nanopolycrystalline have numerous dangling bonds. Both densities of the dangling bonds were evaluated.