Sol-Gel Route for the Synthesis of CoFe 2- x Er x O 4 Nanocrystalline Ferrites and the Investigation of Structural and Magnetic Properties for Magnetic Device Applications.

Autor: Islam M; Bangladesh Atomic Energy Regulatory Authority (BAERA), E-12/A, Agargaon, Dhaka 1207, Bangladesh., Khan MKR; Department of Physics, University of Rajshahi, Rajshahi 6205, Bangladesh., Kumar A; Department of Physics, University of Rajshahi, Rajshahi 6205, Bangladesh., Rahman MM; Department of Physics, University of Rajshahi, Rajshahi 6205, Bangladesh., Abdullah-Al-Mamun M; Department of Physics, Rajshahi University of Engineering & Technology, Rajshahi 6204, Bangladesh., Rashid R; Materials Science Division, Atomic Energy Center, Dhaka 1000, Bangladesh., Haque MM; Materials Science Division, Atomic Energy Center, Dhaka 1000, Bangladesh., Sarker MSI; Department of Physics, University of Rajshahi, Rajshahi 6205, Bangladesh.
Jazyk: angličtina
Zdroj: ACS omega [ACS Omega] 2022 Jun 06; Vol. 7 (24), pp. 20731-20740. Date of Electronic Publication: 2022 Jun 06 (Print Publication: 2022).
DOI: 10.1021/acsomega.2c00982
Abstrakt: This study reports the formation of Er-doped nanocrystalline cobalt ferrite with the formula CoFe 2- x Er x O 4 (0.0 ≤ x ≤ 0.10) from nontoxic metal precursors Co(NO 3 ) 2 ·6H 2 O, Fe(NO 3 ) 3 ·9H 2 O, and Er(NO 3 ) 3 ·5H 2 O through an easy and economical sol-gel route in which citric acid is served as the chelating agent. The as-prepared powder was annealed at 700 °C for 3 h in ambient air to get the required spinel structure. The annealed samples were subjected to structural and magnetic characterization. The X-ray diffraction (XRD) data of the samples confirmed the cubic spinel structure formation. The average crystallite size evaluated from XRD data increased from 21 to 34 nm with the substitution of Er due to the larger atomic size of Er 3+ than Fe 3+ . Moreover, the crystallite size obtained from XRD data are well matched with the particle size measured from transmission electron microscopy images. The lattice parameters obtained from XRD data agree well with the values estimated from theoretical cation distribution and Rietveld refinement calculation. The hysteresis curve exhibits the particles are soft ferromagnetic and the coercivity increased from 54.7 to 76.6 kA/m with maximum saturation magnetization, M s = 61 emug -1 for 0.10 Er content. The squareness ratios were found to be less than 0.5, which indicates the single-domain nature of our particles. The blocking temperature measured from field cooled-zero field cooled curves is T B > 350 K for all the samples, which is much higher than the room temperature (300 K). The enhancement of saturation magnetization and coercivity has been explained based on the crystallite size, anisotropy constant, and cation distribution. Thus, the structural and magnetic properties of CoFe 2 O 4 nanoparticles (NPs) can be tuned by Er incorporation and these NPs can be applied in different soft magnetic devices.
Competing Interests: The authors declare no competing financial interest.
(© 2022 The Authors. Published by American Chemical Society.)
Databáze: MEDLINE
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