Correlation between electrospinning parameters and magnetic properties of BiFeO3 nanofibers

Abstract

BiFeO 3 nanofibers of different morphologies and dimensions were produced by electrospinning varying the collector and thermal treatment. By thermogravimetric analyses (TGA) the thermal behavior of the as-spun nanofibers was studied. The morphology of the nanofibers was examined by transmission and scanning electron microscopy (TEM and SEM, respectively) while the chemical composition and crystal structure were analyzed by energy dispersive x-ray spectrometry (EDS) and wide angle x-ray diffraction (WAXD). A vibrating sample magnetometer (VSM) was used to evaluate the magnetic properties. Different types of mats with different nanofibers´dimen-sions were obtained; while some nanofibers were interconnected, others were completely separated and aligned. The thinnest nanofibers were obtained using an aluminum substrate with folds and after annealing at 550 ∘ C. All samples annealed at this temperature formed pure BiFeO 3 , while samples annealed at 550 and 750 ∘ C formed an additional Bi 2 Fe 4 O 9 phase. No iron impurities were detected; the crystallite size of all the nanofibers was between 30 and 36 nm. The saturation magnetization increased with the decrease of the nanofiber´s diameter and increase of nanofibers interconnectivity. Thus, this ferromagnetism behavior was attributed to the suppression of the spiral spin structure of BiFeO 3 (which has a 62 nm period) and to the morphology of interconnected nanofibers.

Reusable BiFeO3 Nanofiber-Based Membranes for Photo-activated Organic Pollutant Removal with Negligible Colloidal Release

“…Only 26% (weight) of BFO nanofibers remains after annealing, which is consistent with previous reports using similar synthesis protocols. 54,55 Based on this measurement, we can provide a fair estimate of the BFO nanofibers weight of 0.6, 1.2, 2.4, 3.6, and 6.0 mg for samples obtained after 0.5, 1, 2, 3, and 5 min, respectively.…”

Theoretical study and development of photonic devices and sensors

“…Moreover, R. E. S. Bretas et al demonstrated that the magnetic properties (i.e. saturation magnetization) of BiFeO3 nanofibers produced by electrospinning increased with the decrease of the nanofibers' diameter and increase of nanofibers interconnectivity [146].…”