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Single-phase cobalt ferrite (CoFe2O4) nanopowder, with average particle size ∼20 nm, has been synthesised using an ethylene diamine tetra acetic acid precursor-based method. CoFe2O4nanopowder was obtained by calcining precursor at 550°C for 4 h in air. The change of microstructure of the synthesised CoFe2O4with increasing sintering temperature was studied using scanning electron microscopy. DC electrical resistivities of unsintered and sintered samples were measured using a two-probe method. Room temperature magnetic hysteresis measurement revealed that the synthesised CoFe2O4nanopowder exhibited ferromagnetic behaviour at room temperature with saturation magnetisation of 67.55 emu/g and coercivity of 1645.24 Oe. [ABSTRACT FROM PUBLISHER]

A novel 'one-pot' synthetic method has been reported for the preparation of (NiFe2O4)x-(BaFe12O19)1−x composites. The synthesized composites were characterized using thermogravimetric analysis, differential scanning calorimetric analysis, X-ray diffraction, dynamic light scattering technique, scanning electron microscopy, and vibrating sample magnetometer. The (NiFe2O4)x-(BaFe12O19)1−x composites prepared by this method showed crystallographically two phase behavior, but magnetically a good single phase exchange spring-coupled behavior with high saturation magnetization as well as high coercivity. [ABSTRACT FROM AUTHOR]

An ethylenediamine tetraacetic acid (EDTA) precursor-based chemical method has been reported for preparation of single-phase barium hexaferrite nanopowder. Synthesized powders were characterized by thermogravimetric analysis, differential scanning calorimetric analysis, x-ray diffraction, particle size analysis, transmission electron microscopy, and scanning electron microscopy. DC electrical resistivity and magnetic properties of synthesized BaFe12O19 were measured by using a two-probe method and a vibrating sample magnetometer, respectively. This EDTA precursor-based method has the capability of producing nanostructured pure single-phase BaFe12O19 powder at a comparatively lower calcination temperature and offers the potential of a simpler, more cost-effective route than other reported methods. [ABSTRACT FROM AUTHOR]

Biogenic synthesis of gold nanoparticles have been accomplished using dried biomass of two high altitude lichen species, collected from the alpine region of Eastern Himalaya in Arunachal Pradesh state of North East India, without addition of any external reducing or stabilizing chemicals. The nanoparticles were characterised by UV–visible, FT-IR spectroscopy, powder X-ray diffraction (XRD), and transmission electron microscopy (TEM). The as-obtained gold nanoparticles showed surface plasmon resonance (SPR) band at ~535 nm. The XRD study furnished evidence for the formation of face-centered cubic structure of gold nanomaterials. The nanoparticles produced with Acroscyphus sp. consisted of multiply twinned quasi-spherical and prismatic shapes while those accessed with Sticta sp. are exclusively multiply twinned. The biomatrix loaded gold nanomaterial exhibited pronounced antioxidant activity. [ABSTRACT FROM AUTHOR]