SYNTHESIS AND CHARACTERIZATIONOF MANGANESE FERRITE NANOPARTICLESDOPED WITH DIVALENTTRANSITION METAL IONS AND TRIVALENTRARE Earth IONS

Abstract

The fascinating and unusual properties of nanoparticles have aroused interest in newlinethe development of magnetic nanoparticles for a variety of applications in newlinedifferent areas of science and technology. Ferrite nanoparticles have been newlineextensively investigated and applied in the field of biomedical applications, waste newlinewater treatment technology, magnetic resonance imaging (MRI) contrasting newlineagents, drug delivery agents, photocatalysis, ferrofluid technology etc. Such a newlinewide range of applications of ferrites are based on their electrical, magnetic and newlineoptical properties which are found to be dependent on their size, composition and newlineprocessing parameters. Nanoparticles have large surface to volume ratio which newlinegive rises to surface effects, thereby resulting in different properties from their newlinebulk counterparts. Apart from their composition, electrical properties being a newlinefunction of crystallite size are expected to be different in their bulk form and nano newlineform. In case of magnetic properties, various phenomena such as the case of newlinesuperparamagnetism, spin canting, enhanced anisotropy, reduction in saturation newlinemagnetization, single domain nature etc may arise in ferrite nanoparticles. Among newlinethe variety of useful ferrites, manganese ferrite is an important one with a mixed newlinespinel structure. The spinel structure is formed by FCC packing of oxygen ions newlineleaving behind two interstitial sites namely the tetrahedral site (A site) and the newlineoctahedral site (B site). Manganese ferrite belongs to the category of mixed spinel newlineferrite in which a fraction of manganese ion occupies the B site (0.2 in most newlinecases). The cation distribution plays a dominant role in determining its properties newlineand a redistribution of cations might have resulted from the substitution of newlinedifferent dopants in the basic ferrite newline