Kumar, B.S.Shanmugharaj, A.M.Kalpathy, S.K.Anandhan, S.2020-03-312020-03-312017Ceramics International, 2017, Vol.43, 9, pp.6845-6857https://idr.nitk.ac.in/handle/123456789/13467In this study, we report for the first time the synthesis of nickel titanate (NTO) nanofibers containing a mixture of ilmenite and spinel phases of NTO, at an atypical low temperature. Precursor nanofibers produced by sol-gel electrospinning were calcined at three different temperatures to produce the NTO nanofibers. Thermal analysis along with X-ray photoelectron spectroscopy confirmed the formation of non-crystalline stable phases of TiN and Ti-O-N that restrained the formation of ilmenite NTO, and the Ni-rich environment pushed the Ti atoms to tetrahedral sites to form a defective spinel structure. The crystallite size of spinel NTO was observed to increase as a function of the calcination temperature above 700 C, as the activation energy for coalescence and growth of spinel NTO was favorable. NTO nanofibers obtained above the calcination temperature of 700 C exhibited new band gap energy around 2.5 eV in Tauc plot. Oxygen vacancies in these ceramic nanofibers decreased as the calcination temperature was increased. A hypsochromic shift of 20 nm in the photoluminescence spectra suggested that the material had a Ni2+ rich NTO (spinel). 2017 Elsevier Ltd and Techna Group S.r.l.Article