Synthesis and Magnetic Properties of Hematite Particles in a ‘‘Nanomedusa’’ Morphology

Znanstveni rad - Izvorni znanstveni rad

• Autor: Jin Bae Lee
• Autor: Hae Jin Kim
• Autor: Janez Lužnik
• Autor: Andreja Jelen
• Autor: Damir Pajić
• Autor: Magdalena Wencka
• Autor: Zvonko Jagličić
• Autor: Anton Meden
• Autor: Janez Dolinšek
• Autorova ustanova: Sveučilište u Zagrebu; Prirodoslovno-matematički fakultet; (Fizički odsjek)
• Znanstveno / umjetničko područje, polje i grana: PRIRODNE ZNANOSTI; Fizika

Sažetak (engleski)

We present the synthesis, characterization, and magnetic properties of hematite particles in a peculiar “nanomedusa” morphology. The particles were prepared from an iron-silica complex by a hydrothermal process in a solution consisting of ethyl acetate and ethanol. The particles’ morphology, structure, and chemical composition were investigated by transmission electron microscopy, powder X-ray diffraction, and scanning electron microscope equipped with an energy-dispersive X-ray spectrometer. The “hairy” particles consist of a spherical-like core of about 100 nm diameter and fibrous exterior composed of thin “legs” of 5 nm diameter grown along one preferential direction. The particles’ cores are crystalline and undergo a magnetic phase transition to a weakly ferromagnetic state at a temperature of 930K thatmatches reasonably the N´eel temperature of bulk hematite. However, unlike bulk hematite that undergoesMorin transition to an antiferromagnetic state around room temperature and small hematite nanoparticles that are superparamagnetic, the “nanomedusa” particles remain weakly ferromagnetic down to the lowest investigated temperature of 2K. Each particle thus represents a nanodimensional “hairy” ferromagnet in a very broad temperature interval, extending much above the room temperature. Such high-temperature ferromagnetic nanoparticles are not frequently found among the nanomaterials.

• Ključne riječi (engleski): hematite; nanoparticles; morphology; magnetism
• Jezik: engleski
• Vrsta publikacije: Znanstveni rad - Izvorni znanstveni rad
• Status objave: Objavljen
• Vrsta recenzije: Recenziran - međunarodna recenzija
• Verzija publikacije: Objavljena verzija rada (izdavačev PDF)
• Naslov časopisa: Journal of Nanomaterials
• Brojčani podaci: vol. 2014, 902968-9
• p-ISSN: 1687-4110
• e-ISSN: 1687-4129
• DOI: https://doi.org/10.1155/2014/902968
• URN:NBN: urn:nbn:hr:217:063978
• Datum objave publikacije: 2014
• Projekt: Šifra: 119-1191458-1017; Naziv (hrvatski): Nanomagneti; Voditelj: Krešo Zadro; Pravna nadležnost: Hrvatska; Financijer: MZOS; Linija financiranja: ZP
• URL dokumenta: https://www.hindawi.com/journals/jnm/2014/902968/
• Vrsta resursa: Tekst
• Prava pristupa: Otvoreni pristup
• Javna napomena: © 2014 Jin Bae Lee et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Received 22 August 2014; Revised 10 November 2014; Accepted 10 November 2014; Published 20 November 2014.
• Datum i vrijeme pohrane: 2019-11-27 21:34:09