Dynamic percolation of electric conductivity and a trend towards fractal skeletal structuring in a random ensemble of magnetized nanodust

TL;DR

This paper models the electrodynamic aggregation of magnetized nanodust, revealing dynamic percolation of electric conductivity and a trend towards fractal structuring driven by magnetic and electric interactions.

Contribution

It introduces a numerical model for magnetized nanodust aggregation, demonstrating how magnetic fields influence filament formation and percolation thresholds in a novel way.

Findings

Percolation threshold decreases with volume fraction compared to carbon nanotubes.

Filament pinching dynamics show interplay of magnetic and electric mechanisms.

Evidence of fractal skeletal structuring at larger scales.

Abstract

Numerical modeling of electrodynamic aggregation is carried out for a random ensemble of magnetized nanodust taken as a many body system of strongly magnetized thin rods (i.e., one-dimensional static magnetic dipoles), which possess electric conductivity and static electric charge, screened with its own static plasma sheath. The self-assembling of quasi-linear filaments from an ensemble of randomly situated basic blocks and the electric short-circuiting between biased electrodes are shown to be supported by the alignment of blocks in an external magnetic field. Statistical analysis of short-circuiting time allows tracing the dynamic percolation of electric conductivity and shows a decrease of percolation threshold for volume fraction, as compared with the observed percolation of carbon nanotubes in liquids and polymer composites. Modeling of short-circuiting stage of evolution is continued with tracing the dynamics of pinching of electric current filaments to show the interplay of all the magnetic and electric mechanisms of filaments networking. A trend towards a fractal skeletal structuring (namely, repeat of original basic block at a larger length scale) is illustrated with the evidence for generation of a bigger magnetic dipole.