Indian Journal of Science and Technology
Year: 2022, Volume: 15, Issue: 27, Pages: 1356-1363
D Rajasekhar1, Charan Kuchi2, Bodicherla Naresh1, G S Harish3, P Sreedhara Reddy1*
1Department of Physics, Sri Venkateswara University, Tirupati-517502, A.P, India
2Department of Physics, Indian Institute of Technology, Tirupati, India
3Government Polytechnic Pillaripattu, Nagari, A.P, India
Email: [email protected]
Received Date:22 February 2022, Accepted Date:21 June 2022, Published Date:14 July 2022
Objectives: To find how annealing temperature affected the morphological, structural, and magnetic properties of nickel oxide (NiO) nanofibers (NFs). Also to establish a link between magnetic characteristics and the vacancy defects generated by particle size effects. Methods: Cost-effective electrospinning method is used to fabricate NiO NFs by using Nickel nitrate hexahydrate Nickel (II) nitrate as a precursor and polyvinylpyrrolidone (PVP) as a polymer. Annealing of precursor NFs helps it to transform to NiO NFs. Scanning Electron Microscope (SEM) and X-ray diffraction (XRD) are used to study the morphological and structural properties of NiO NFs. We inspected elemental composition and molecular interactions with an X-ray photoelectron spectrometer (XPS) and Raman spectra. Vibrating sample magnetometer (VSM) measurements probe the magnetic properties. Findings: Changing the annealing temperature allows us to tune the particle size. The average NF diameter was reduced with annealing from 17330 nm for as-spun NFs to 11013 nm for 800◦C annealed NiO NFs. With a rise in annealing temperature from 400◦C to 800◦C, the particle diameter increased from 9.16 nm to 27 nm. We observed field-dependent magnetization for NiO NFs annealed at 400◦C, i.e. ferromagnetic (FM) with susceptibility of 0.3341 at lower magnetic fields and antiferromagnetic (AF) with susceptibility of 0.0096 at higher applied magnetic fields. With the rise in annealing temperature, the magnetization reduced. As shown in XPS studies, we estimated the variation in Ni vacancies and oxygen concentration with annealing temperature may be the reason for a change in the magnetic properties of NiO NFs, because of its particle size variation with annealing. Novelty: From the experimental results, we inferred a probable cause for the FM properties in the AF material. Because of their anomalous magnetic property, i.e. field-dependent magnetization, we can use NiO NFs annealed at 400◦C as a material for spintronic switching devices.
Keywords: Electrospinning; Nanofibers; Magnetic properties; Annealing temperature; Particle size
© 2022 Rajasekhar et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Published By Indian Society for Education and Environment (iSee)
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