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P V Vanitha

Publications and source records attributed to P V Vanitha.

2 recordsLinked to original sources
PubMed2005

Perpendicular magnetization in self-assembled films of citrate-capped gamma-Fe2O3 nanocrystals on Si(100) surfaces.

gamma-Fe2O3 nanocrystals capped with citrate and octylamine have been chemically prepared. The octylamine-capped nanocrystals exhibit a tendency to form ordered lattices. Films of nanocrystals of varying thickness (454, 720, and 1400 microg/cm2 in the case of citrate-capped nanocrystals and 300 microg/cm2 in the case of octylamine-capped nanocrystals) have been prepared on Si(100) substrates by drop casting and have been characterized by X-ray diffraction, scanning electron microscopy, and atomic force microscopy. Magnetic measurements have been carried out on the films as well as on nanocrystal powders. The films of citrate-capped gamma-Fe2O3 nanocrystals exhibit enhanced perpendicular magnetization, with the anisotropy depending on the film thickness.

Amines↗
PubMed2003

Phase separation in metal oxides.

A fascinating phenomenon, recently found to occur in certain transition-metal oxides, is phase separation wherein pure, nominally monophasic oxides of transition metals with well-defined compositions separate into two or more phases over a specific temperature range. Such phase separation is entirely reversible, and is generally the result of a competition between charge-localization and -delocalization, the two situations being associated with contrasting electronic and magnetic properties. Coexistence of more than one phase, therefore, gives rise to electronic inhomogeneity and a diverse variety of magnetic, transport, and other properties, not normally expected of the nominal monophasic composition. An interesting feature of phase separation is that it covers a wide range of length scales anywhere between 1-200 nm. While cuprates and manganates, especially the latter, provide excellent examples of phase separation, it is possible that many other transition-metal compounds with extended structures will be found to exhibit phase separation.

Journal Article↗