Structural properties of ultrafine Ba-hexaferrite nanoparticles

Journal Article · Sat Dec 15 00:00:00 EST 2012 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/J.JSSC.2012.07.043· OSTI ID:22149912

Makovec, Darko ^[1]; Primc, Darinka; Sturm, Saso ^[1]; Kodre, Alojz ^[2]; Hanzel, Darko ^[1]; Drofenik, Miha ^[3]

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1. Jozef Stefan Institute, Jamova ulica 39, SI-1000 Ljubljana (Slovenia)
2. Faculty of Mathematics and Physics, University of Ljubljana, Jadranska ulica 19, SI-1000 Ljubljana (Slovenia)
3. Faculty for Chemistry and Chemical Engineering, University of Maribor, Smetanova ulica 17, SI-2000 Maribor (Slovenia)

Crystal structure of ultrafine Ba-hexaferrite (BaFe{sub 12}O{sub 19}) nanoparticles was studied using X-ray diffractometry (XRD), high-resolution transmission electron microscopy (HRTEM), energy-dispersive X-ray spectroscopy (EDXS), X-ray absorption fine structure (XAFS), and Moessbauer spectroscopy (MS), to be compared to the structure of larger nanoparticles and the bulk. The nanoparticles were synthesized with hydrothermal treatment of an appropriate suspension of Ba and Fe hydroxides in the presence of a large excess of OH{sup -}. The ultrafine nanoparticles were formed in a discoid shape, {approx}10 nm wide and only {approx}3 nm thick, comparable to the size of the hexagonal unit cell in the c-direction. The HRTEM image analysis confirmed the hexaferrite structure, whereas EDXS showed the composition matching the BaFe{sub 12}O{sub 19} formula. XAFS and MS analyses showed considerable disorder of the structure, most probably responsible for the low magnetization. - Graphical abstract: Left: HREM image of an ultrafine Ba-hexaferrite nanoparticle (inset: TEM image of the nanoparticles); Right: the experimental HRTEM image is compared with calculated image and corresponding atomic model. Highlights: Black-Right-Pointing-Pointer Crystal structure of ultrafine Ba-hexaferrite (BaFe{sub 12}O{sub 19}) nanoparticles was compared to the structure of the bulk. Black-Right-Pointing-Pointer Thickness the discoid nanoparticles was comparable to the size of the hexagonal unit cell in the c-direction. Black-Right-Pointing-Pointer Considerable disorder of the nanoparticles' structure is most probably responsible for their low magnetization.

• OSTI ID: 22149912
• Journal Information: Journal of Solid State Chemistry, Vol. 196; Other Information: Copyright (c) 2012 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
77 NANOSCIENCE AND NANOTECHNOLOGY
ABSORPTION
ABSORPTION SPECTROSCOPY
CRYSTAL STRUCTURE
FERRITES
FINE STRUCTURE
IMAGE PROCESSING
IMAGES
MAGNETIZATION
MOESSBAUER EFFECT
NANOSTRUCTURES
PARTICLES
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION
X-RAY SPECTROSCOPY