Large negative magnetoresistance and strong localization in highly disordered electrospun pregraphitic carbon nanofiber

A highly disordered pregraphitic carbon nanofiber with the product of its quasi-Fermi wave vector and mean free path close to 1 was fabricated using electrospinning technique. Strong localization made the conductivity vary with temperature as ln σ ∝ T − 1 ∕ 2 from 300 to 5 K , suggesting variable range hopping as the conductivity mechanism, and resulted in a large negative magnetoresistance from 300 K down to 1.9 K that can still be quantitatively described using weak localization and electron interaction models.