Negative differential resistance in amorphous carbon/zirconium oxide nanocomposites: mechanisms and characterisation

Devices exhibiting negative differential resistance (NDR) characteristics are fundamental in constructing many electronic components, where NDR plays a crucial role in various power electronic applications. This study presents a ground-breaking development in our continuous exploration of NDR behaviour observed in nanocomposites. These devices are synthesised using an economical and straightforward sol-gel technique. We focused on a pyrogallol formaldehyde (PF) matrix enriched with zirconium oxide (ZrO₂) nanopowder. Our approach involved incorporating an amount of ZrO₂ nanopowder into the carbon matrix, with the additive weight set at 10% of the PF matrix mass ratio. Initially, ZrO₂ nanoparticles were synthesised and embedded within (PF) host matrix using the sol-gel method under atmospheric conditions. Subsequently, PF/ZrO₂ nanocomposites were produced through a straightforward pyrolysis process, conducted for 2 h at the predetermined temperature in an inert atmosphere. Then, the structural, morphological, and electrical properties of the zirconium oxide/carbon nanocomposites (PFZr) were investigated. The analyses confirm the successful incorporation of nanosized zirconium particles into the organic matrix. Electrical conductivity measurements show a temperature-dependent transformation from an insulating xerogel to conductive carbon particles during pyrolysis, indicating the formation of continuous conducting channels. In addition, current-voltage (I-V) characteristics exhibit a promising (NDR) phenomenon, assigned to the Joule heating effect. This study also explores various prepared and measured parameters influencing the NDR response. This work highlights the potential of PFZr nanocomposites as a smart material for future technologies.