Tunable electrical conductivity of nickel-polypyrrole microparticle suspensions under electric and magnetic fields

Abstract

This study presents a new class of low-cost composite materials based on a silicone oil suspension containing nickel-based hybrid microparticles in equal volume fractions. Two types of suspensions were prepared using magnetic particles with different compositions. The nickel content of the hybrid microparticles was 78.3 and 83.4 wt% nickel core, respectively, with the rest being a polypyrrole coating composed of nanoparticles and nanotubes. Utilizing a specialized experimental setup, we investigated the influence of nickel concentrations on the electrical conduction properties of the suspensions. The measurements were performed under electric and combined electric and magnetic fields. Our findings demonstrate that the electrical conductivity has a non-linear response with external fields and it can be effectively tuned through the nickel content and the external fields. A model was developed to understand the observed trends. These findings have significant implications for the design and optimization of advanced materials in applications requiring the precise control of electrical properties under varying field conditions.