Low frequency dielectric response mechanism of bamboo charcoal

Abstract

The carbonization of bamboo at 400 °C–700 °C resulted in the formation of graphite crystals embedded in amorphous carbon. The high dielectric constants (≈10³ at 1 Hz) of these carbon materials were attributed to the presence of polar groups such as -OH, -NH₂ and -COOH with marginal contribution from interfacial polarization. The dielectric constants were observed to be frequency-dependent and found to be decreased with increasing frequency. The measured dielectric loss was also found to be decreasing with increasing frequency. Conductance dominant dielectric loss observed in 400 °C–600 °C annealed samples was further supported by the Cole-Cole plot. Maxwell–Wagner–Sillars interfacial polarization relaxation along with conduction loss was observed only for the 700 °C annealed sample.

Keywords:

• Carbon materials
• microstructure
• dielectric properties
• Maxwell–Wagner–Sillars interfacial dielectric relaxation

Competing interest statement

The authors confirm that there are no relevant financial or non-financial competing interests to the report.