Investigation of dielectric relaxation behavior of electrospun titanium dioxide nanofibers using temperature dependent impedance spectroscopy

The electrospinning method has been utilized in the fabrication of titanium dioxide nanofibers (TNFs) with an average diameter of ∼50 nm and length of ∼100 μm. Effect of temperature on the dielectric relaxation behavior of the fabricated nanofibers have been studied using AC impedance spectroscopy. The morphological, structural and compositional aspects as well as the optical properties of the TNFs have been investigated by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), energy-dispersive x-ray spectroscopy (EDX) and ultraviolet–visible (UV–vis) absorption spectrum. The permittivity behavior of the device at the frequency below 102 Hz shows the relaxation contribution along with the electrode polarization. Dielectric loss peak in loss tangent also confirms the presence of relaxing dipoles in TNFs. The AC conductance as a function of frequency confirms the semiconducting nature of TNFs and obeys Jonscherʹs power law except a small deviation in the low frequency region. DC conductivity increases with increase in temperature.