Effect of mechanical milling on the structural, magnetic and dielectric properties of coprecipitated ultrafine zinc ferrite

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS

卷:269

Article

Shenoy, SD ; Joy, PA ; Anantharaman, MR

关键词: magnetic nanoparticles;    zinc ferrite;    high-energy ball milling;    superparamagnetism;    spinels;    strain parameter;    dielectric;    interfacial polarisation;    spin polarised tunnelling;    Lab VIEW;   

DOI  :  10.1016/S0304-8853(03)00596-1

来源: Elsevier

【 摘 要 】

Nanosized ZnFe(2)O(4) particles containing traces of alpha-Fe(2)O(3) by intent were produced by low temperature chemical coprecipitation methods. These particles were subjected to high-energy ball milling. These were then characterised using X-ray diffraction, magnetisation and dielectric studies. The effect of milling on zinc ferrite particles have been studied with a view to ascertaining the anomalous behaviour of these materials in the nanoregime. X-ray diffraction and magnetisation studies carried out show that these particles are associated with strains and it is the surface effects that contribute to the magnetisation. Hematite percentage, probably due to decomposition of zinc ferrite, increases with milling. Dielectric behaviour of these particles is due to interfacial polarisation as proposed by Koops. Also the defects caused by the milling produce traps in the surface layer contributes to dielectric permittivity via spin polarised electron tunnelling between grains. The ionic mechanism is enhanced in dielectrics with the rise in temperature which results in the increase of dielectric permittivity with temperature. (C) 2003 Published by Elsevier B.V.

【 授权许可】

Free