Accession Number:

ADP012205

Title:

Production and Magnetic Properties of Nanocomposites Made of Ferrites and Ceramic Matrices

Descriptive Note:

Corporate Author:

TOYOHASHI UNIV OF TECHNOLOGY (JAPAN) DEPT OF PRODUCTION SYSTEMS ENGINEERING

Report Date:

2001-11-01

Pagination or Media Count:

6.0

Abstract:

This investigation deals with the production of materials containing a dispersion of magnetic nanoparticles in an insulating matrix. Such a distribution of magnetic centers is expected to absorb electromagnetic radiation in a range of wavelengths. Wustite-magnetite and magnesia-magnesioferrite nanocrystalline ceramics have been prepared by mechanical milling and spark plasma sintering. As-milled powders have a nanocrystalline structure in both systems. Low energy milling gives rise to an increasingly higher volume fraction of wustite as a function of milling time in the Fe1-xO-Fe3O4 system. Similar results are obtained in the MgO-MgFe2O4 system with increasingly larger amounts of MgFe2O4 produced by milling. Composites of magnetic particles Fe3O4 or MgFe2O4 in a nonconductive matrix FeO or MgO, respectively are found in the sintered samples. Measurement of magnetic properties can be used to determine conclusively the nature of the developed phases and the effect of grain size.

Subject Categories:

  • Laminates and Composite Materials

Distribution Statement:

APPROVED FOR PUBLIC RELEASE