Effect of vanadium ion implantation on the crystallization kinetics and phase transformation of electrospun TiO2 nanofibers

• Published in: Applied physics. A, Materials science & processing Materials science & processing, 2015-08, Vol.120 (2), p.623-634
• Main Authors: Albetran, H., O’Connor, B. H., Prida, V. M., Low, I. M.
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Condensed Matter Physics; Machines; Manufacturing; Nanotechnology; Optical and Electronic Materials; Physics; Physics and Astronomy; Processes; Surfaces and Interfaces; Thin Films
• ISSN: 0947-8396; 1432-0630
• DOI: 10.1007/s00339-015-9227-8

The influence of V ion implantation on the thermal response of electrospun amorphous TiO 2 nanofibers was studied with reference to structural phase transformation behavior, using in situ synchrotron radiation diffraction (SRD) measurements from room temperature to 1000 °C. Analysis of the SRD data provided activation energies for amorphous-to-crystalline TiO 2 (anatase and rutile) and anatase-to-rutile transformations, and also assessments of the influence of V ion implantation on microstructure development during calcination using estimates of crystallite size and microstrain. Non-implanted nanofibers were initially amorphous, with crystalline anatase first appearing at 600 °C, followed by rutile at 700 °C. The corresponding activation energies were 69(17) kJ/mol for the amorphous-to-crystalline TiO 2 transformation and 129(5) kJ/mol for the anatase-to-rutile transformation. V ion implantation resulted in a lowering of the temperature at which each crystalline phase first appeared, with both phases being initially observed at 500 °C and with the anatase-to-rutile transformation being accelerated relative to the non-implanted sample. The effect of V ion implantation is seen through the substantial reduction in activation energies, which are 25(3) kJ/mol for amorphous-to-crystalline TiO 2 and 16(3) kJ/mol for anatase-to-rutile transformations.