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Author Shenoy, S. D. ♦ Joy, P. A. ♦ Anantharaman, M. R.
Source CUSAT-Thesis
Content type Text
Publisher ELSEVIER
File Format PDF
Language English
Subject Domain (in DDC) Natural sciences & mathematics ♦ Chemistry & allied sciences ♦ Technology
Subject Keyword Magnetic nanoparticles ♦ Zinc ferrite ♦ High-energy ball milling ♦ Superparamagnetism ♦ Spinels ♦ Dielectric ♦ Interfacial polarisation ♦ Spin polarised tunnelling ♦ Strain parameter ♦ Lab VIEW
Abstract Nanosized ZnFe2O4 particles containing traces of a-Fe2O3 by intent were produced by low temperature chemicalcoprecipitation methods. These particles were subjected to high-energy ball milling. These were then characterised usingX-ray diffraction, magnetisation and dielectric studies. The effect of milling on zinc ferrite particles have been studiedwith a view to ascertaining the anomalous behaviour of these materials in the nanoregime. X-ray diffraction andmagnetisation studies carried out show that these particles are associated with strains and it is the surface effects thatcontribute to the magnetisation. Hematite percentage, probably due to decomposition of zinc ferrite, increases withmilling. Dielectric behaviour of these particles is due to interfacial polarisation as proposed by Koops. Also the defectscaused by the milling produce traps in the surface layer contributes to dielectric permittivity via spin polarised electrontunnelling between grains. The ionic mechanism is enhanced in dielectrics with the rise in temperature which results inthe increase of dielectric permittivity with temperature.
ISSN 03048853
Education Level UG and PG
Learning Resource Type Article
Journal Journal of Magnetism and Volume
Volume Number 269
Issue Number 2
Page Count 10
Starting Page 217
Ending Page 226