Magnetotactic bacteria produce exquisitely ordered chains of uniform magnetite (Fe(3)O(4)) nanocrystals, and the use of the bacterial mms6 protein allows for the shape-selective synthesis of Fe(3)O(4) nanocrystals. Cobalt ferrite (CoFe(2)O(4)) nanoparticles, on the other hand, are not known to occur in living organisms. Here we report on the use of the recombinant mms6 protein in a templated sy...

We report on the frequency (f1⁄420 Hz–1 MHz) and temperature (T1⁄4300–600 K) dependent electrical properties of gadolinium (Gd) substituted cobalt ferrite (CoF2 xGdxO4 (CFGO); x1⁄40.00–0.40). Gd-substituted cobalt ferrites crystallize in cubic inverse spinel phase. CFGO materials exhibit lattice parameter expansion from 8.373 Å (x1⁄40.0) to 8.422 Å (x1⁄40.4) due to the larger ionic radius of Gd...

The dependence of the magnetostrictive properties of cobalt ferrite on the size distribution of thepowder used in deriving the samples from traditional ceramic approach is presented. Sample obtained by combining the smallest and largest particle size distributions gave the highestmagnetostriction and strain sensitivity (216 ppm and 1.34 nm/A, respectively), for measurementin parallel direction ...

The temperature dependence of the magnetic properties of titanium modified cobalt ferrite is presented. The change of maximum magnetization obtained at H ≈ 2.4 MA/m between any two temperatures increases systematically with composition, which is desirable for applications in devices. Variation in magnetocrystalline anisotropy and coercivity were different from previous studies on cation substit...

In this report, we demonstrate a unique method for embedding magnetic structures inside a microfluidic channel for cell isolation. We used a molding process to fabricate these structures out of a ferrofluid of cobalt ferrite nanoparticles. We show that the embedded magnetic structures significantly increased the magnetic field in the channel, resulting in up to 4-fold enhancement in immunomagne...

We report on the stabilization of nanoparticle-decorated microbubbles for long periods of time using a synergism between a soluble surfactant and nanoparticles. The soluble surfactant is the perfluoroalkyl phosphate C8F17(CH2)2OP(O)(OH)2 (labeled F8H2Phos) and the nanoparticles (NPs) are 20-25 nm cobalt ferrite (CoFe2O4). The NP-F8H2Phos system has been studied by dynamic light scattering, dyna...

We have studied the magnetic properties and the composition of cobalt ferrite single crystal films on SrTiO3 : Nb grown by infrared pulsed-laser deposition. Mössbauer spectra have been recorded from both the target used to grow the films and the films themselves. The Mössbauer spectra of the target taken at low temperatures show a strong dependence of the recoil free fraction of the octahedral ...

In situ soft X-ray absorption spectroscopy (XAS) was employed to study the adsorption and dissociation of carbon monoxide molecules on cobalt nanoparticles with sizes ranging from 4 to 15 nm. The majority of CO molecules adsorb molecularly on the surface of the nanoparticles, but some undergo dissociative adsorption, leading to oxide species on the surface of the nanoparticles. We found that th...