Negative differential resistance in nickel doped nano-carbon structures based on pyrogallol-formaldehyde xerogel

Nickel doped nano-carbon structures have been synthesized by sol-gel method. In our approach the xerogel formation was activated by picric acid as catalyst and electric properties were explored by changing the pyrolysis temperature. The obtained electrical conducting carbon (ECC) structures were characterized by various techniques, X-ray diffraction (XRD) and electrical analysis. I(V) characteristic of the ECC pyrolysed at 625ºC temperature range presents a negative differential resistance at room temperature were the behaviour depend on maximum of current applied to the sample. However, the dynamics conductance G(ω) of the sample pyrolysed at 700ºC shows a semi-conducting and metallic behaviours depending on measurement temperature.