Magnetic properties of nanoparticles obtained by different chemical routes.

Publisher: American Scientific Publishers Country of Publication: United States NLM ID: 101088195 Publication Model: Print Cited Medium: Print ISSN: 1533-4880 (Print) Linking ISSN: 15334880 NLM ISO Abbreviation: J Nanosci Nanotechnol Subsets: PubMed not MEDLINE

Original Publication: Stevenson Ranch, CA : American Scientific Publishers, 2001-2021

It is well known that nano-sized materials often present chemical, electronic, magnetic, and mechanical properties that are potentially interesting for many technological applications comparatively to their corresponding bulk properties. This paper describes the main differences in magnetic properties among nanomagnetite powders prepared by three methods: (I) reduction-precipitation of ferric chloride by reaction with Na2SO3; (II) reduction of hematite with coal, and (III) reduction of hematite with hydrogen gas. The obtained materials were characterized by powder X-ray diffraction (XRD), saturation magnetization measurements, and Mössbauer spectroscopy. Saturation magnetization values varied from 60 to 86 J T(-1)kg(-1). XRD and Mössbauer spectroscopy results at 298 K showed the clear effect of the preparation routes on the crystallographic structure and crystallite size of the magnetic species. Magnetite was formed in varying proportions in all samples, with crystallite sizes estimated by Scherrer formula of about 10, 26, and 33 nm for samples prepared by methods (I), (II), and (III), respectively. The Mössbauer spectrum of the sample prepared by method (I) consisted of broad lines and hyperfine field for magnetite lower than that typically reported for the bulk material.

Date Created: 20090514 Date Completed: 20090605 Latest Revision: 20190715

20240829

10.1166/jnn.2009.423

19435085