Magnetoresistive polyaniline-silicon carbide metacomposites: plasma frequency determination and high magnetic field sensitivity

Hongbo Gu; Jiang Guo; Mojammel Alam Khan; David P Young; T D Shen; Suying Wei; Zhanhu Guo

doi:10.1039/c6cp02694j

Magnetoresistive polyaniline-silicon carbide metacomposites: plasma frequency determination and high magnetic field sensitivity

Phys Chem Chem Phys. 2016 Jul 20;18(29):19536-43. doi: 10.1039/c6cp02694j.

Authors

Hongbo Gu¹, Jiang Guo², Mojammel Alam Khan³, David P Young³, T D Shen⁴, Suying Wei⁵, Zhanhu Guo²

Affiliations

¹ Shanghai Key Lab of Chemical Assessment and Sustainability, Department of Chemistry, Tongji University, Shanghai, 200092, China. hongbogu2014@tongji.edu.cn.
² Integrated Composites Lab (ICL), Department of Chemical & Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee 37966, USA. zguo10@utk.edu.
³ Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803, USA.
⁴ State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Hebei 066004, China.
⁵ Department of Chemistry and Biochemistry, Lamar University, Beaumont, TX 77710, USA.

PMID: 27386820
DOI: 10.1039/c6cp02694j

Abstract

The Drude model modified by Debye relaxation time was introduced to determine the plasma frequency (ωp) in the surface initiated polymerization (SIP) synthesized β-silicon carbide (β-SiC)/polyaniline (PANI) metacomposites. The calculated plasma frequency for these metacomposites with different loadings of β-SiC nanoparticles was ranging from 6.11 × 10(4) to 1.53 × 10(5) rad s(-1). The relationship between the negative permittivity and plasma frequency indicates the existence of switching frequency, at which the permittivity was changed from negative to positive. More interestingly, the synthesized non-magnetic metacomposites, observed to follow the 3-dimensional (3-D) Mott variable range hopping (VRH) electrical conduction mechanism, demonstrated high positive magnetoresistance (MR) values of up to 57.48% and high MR sensitivity at low magnetic field regimes.