Nitrogen-doped graphite-like carbon derived from phthalonitrile resin with controllable negative magnetoresistance and negative permittivity

Herein, a nitrogen-doped graphite-like carbon material derived from hybrid phthalonitrile (PN) resin with controllable carbon microstructures including crystalline structures, hybridized carbon configurations, degree of disorder, and nitrogen species such as pyridinic N, pyrrolic N, and graphitic N has been manufactured by high-temperature annealing method. By simply altering these carbon microstructures through annealing temperature, the lowest resistivity of 1.76 Omega center dot cm at 290 K, the negative MR value of - 6.10% at a magnetic field of 9 T and negative permittivity over - 10(5) at low frequency are achieved in the semiconducting nitrogen-doped graphite-like carbon material. The results confirm the decreasing degree of disorder attained from Raman spectroscopy, the increasing ratio of sp(2) and sp(3) hybridized carbon, i.e., C(sp(2))/C(sp(3)), from X-ray photoelectron spectroscopy (XPS), and the rise of charge carrier mobility with increasing the magnetic field from Hall-effect measurement is responsible for the negative MR effect in this nitrogen-doped graphite-like carbon material. The negative permittivity is attributed to the plasma oscillation with delocalized charge carriers by the Drude model and the greatly increasing graphitic N in the carbon microstructures. This work opens a new insight for the applications of carbonized PN resins in the electronic device field.

Automated summary

A nitrogen-doped graphite-like carbon material with controllable carbon microstructures was synthesized from hybrid phthalonitrile resin through high-temperature annealing. By adjusting the annealing temperature, the material exhibited the lowest resistivity of 1.76 Omega center dot cm, a negative magnetoresistance (MR) value of - 6.10% at 9 T, and a negative permittivity over - 10(5) at low frequency. The negative MR effect was attributed to decreased disorder, increased sp(2) and sp(3) hybridized carbon, and enhanced charge carrier mobility with increasing magnetic field. The negative permittivity was explained by the plasma oscillation with delocalized charge carriers and the increased graphitic N in the carbon microstructures. This work provides novel insights for the application of carbonized PN resins in electronic devices.