The magnetic-field-induced birefringence in a ferrofluid composed of spherical cobalt nanoparticles has been studied both experimentally and theoretically. The considerable induced birefringence determined experimentally has been attributed to the formation of chains of nanoparticles. The birefringence has been measured as a function of the external magnetic field and the volume fraction (f) of...

Superparamagnetic single crystal single domain Co nanoparticles of 6 nm in diameter evaporated onto highly pyrolytic oriented graphite spontaneously self-assemble into super structures with an elongated shape. These structures have been studied by optical and scanning electron microscopies, atomic and magnetic force microscopy, electron dispersive X-ray analysis, and SQUID magnetometry. We prop...

In this scientific research work we report a novel method to synthesis Co3O4 nanoparticles via calcinations of cobalt hydroxide which can be conveniently prepared by the Co(NO3 )2.6H2O with different reactants. In order to study the effect of calcination temperature on structure and morphology of the nanoparticles, the calcinations take place at various temperatures (at 300°C, 500°C and 700°C)....

Gold nanoparticles have been proven to act as efficient catalysts for chemical reactions, such as oxidation and hydrogen production. In this review we focus on a different aspect of the catalysis of gold nanoparticles; single-walled carbon nanotube (SWCNT) synthesis. This is not a traditional meaning of catalytic reaction, but SWCNTs cannot be synthesized without nanoparticles. Previously, gold...

Electrochemical post-treatment of ultrathin carbon layer coated cobalt nanoparticles generates a novel electrocatalyst, affording a small overpotential of 333 mV at a current density of 10 mA cm(-2) and a small Tafel slope of ∼58 mV per decade.

Co3O4 nanoparticles were synthesized via a simple Co-precipitation reaction between precursors of cobalt and NH3. The effect of different parameters such as concentration of NH3 and precursors of cobalt on the size and photocatalytic activity of the products was investigated. The achieved nanoparticles were characterized by X-ray powder diffraction analysis, field emission scanning electron mic...

a simple and reliable electrochemical sensor based on cobalt oxide nanoparticles modified glassy carbon electrode (gce/cooxnps) for determination of butylated hydroxyanisole is presented here. the nanoparticles were fabricated by electrodepositing method. the modified electrode shows excellent catalytic activity toward butylated hydroxyanisole oxidation in ph 12.0 phosphate buffer solution (pbs...

Hypodentate diamine cobalt(III) pentammine complexes [Co(NH3)5(NH2(CH2)(n)NH3)](ClO4)4 (8: a: n = 3; b: n = 4; c: n = 6; d: n = 8) have been synthesized via the reaction of [Co(NH3)5(OTf)](OTf)2 (TfOH = CF3SO3H) with the corresponding diamines. The analogous t-boc protected diamine complexes [Co(NH3)5(NH2(CH2)(n)NHt-boc)](ClO4)3 (7a-d) were prepared in 4-26% yield. Low yields for the formation ...

Bimagnetic monodisperse CoFe₂O₄/Fe₃O₄ core/shell nanoparticles have been prepared by solution evaporation route. To demonstrate preferential coating of iron oxide onto the surface of ferrite nanoparticles X-ray diffraction (XRD), High resolution transmission electron microscope (HR-TEM) and Raman spectroscopy have been performed. XRD analysis using Rietveld refinement technique confirms single ...