0000000000214863
AUTHOR
Dmitrijs Jakovlevs
Characterization of Rabbit Mesenchymal Cell Attachment on Calcium Phosphate Surface
In the current study, the effect of three different treated surfaces of hydroxyapatite and β-tricalcium phosphate on mesenchymal cell attachment has been investigated. Calcium phosphate powders have been synthesized, uniaxially pressed, polished and sintered. Mesenchymal cells have been seeded onto unpolished, polished and polished-thermally etched ceramic samples. The ceramic samples have been characterized by XRD, FTIR and SEM. Results have shown that the best cell attachment and morphology are on the unpolished surface indicating that relatively rough surface is better for cell application.
Properties of Ni–Zn ferrite thin films deposited using spray pyrolysis
Abstract Nanocrystalline, homogeneous spinel Ni 1 − x Zn x Fe 2 O 4 thin films were deposited on glass substrates by using spray pyrolysis of metal nitrate aqueous solutions. The thickness of deposited films was below 500 nm, but crystallite size was under 30 nm. It has been shown that the DC resistivity, dielectric loss and optical band gap of deposited films are influenced by the zinc content. High DC resistivity and low dielectric losses of thin Ni 1 − x Zn x Fe 2 O 4 films are explained by mixed n-p conductivity and nanograin structure of spray pyrolysis deposited coatings which are changing with the ratio of Ni/Zn.
Study of the structural phase transformation of iron oxide nanoparticles from an Fe2+ ion source by precipitation under various synthesis parameters and temperatures
Abstract Magnetite nanoparticles were precipitated from a pure aqueous ferrous salt solution in an air atmosphere. The influence of the solution molarity, the rate of precipitator agent addition, stirring time and annealing temperature was studied. The morphology, crystalline phase purity and magnetic properties of the obtained powders were studied by X-Ray powder diffraction (XRD), Scanning electron microscopy (SEM), Differential thermal analysis (DTA), X-ray photoelectron spectroscopy (XPS), X-ray absorption spectroscopy (XAS) and Vibrating sample magnetometer (VSM). The synthesis conditions were seen to have an effect on phase composition. It was possible to obtain near stoichiometric Fe…
Influence of iron non-stoichiometry on spinel zinc ferrite gas sensing properties
Abstract It is demonstrated for the first time that the gas sensing properties of a spinel ferrite complex metal oxide semiconductor can be improved by controlling iron stoichiometry. Conductivity and sensitivity was analyzed for ZnFe2+zO4± spinel type ferrite with z from −0.01 to 0.15. By increasing iron content from z = −0.01 to z = 0.1, sensitivity increases up to 3 times but for samples with z > 0.1 sensitivity drops. It was observed from impedance spectroscopy measurements that resistance decreases with an increase of the iron content. Complex impedance spectra reveal two phases with different resistance attributed to depletion layer (Rd) and bulk (Rb). With increasing iron content inc…
Precipitation synthesis of magnetite Fe3O4 nanoflakes
Precipitation can be applied to synthesize magnetite Fe3O4 nanoflakes in an ambient air atmosphere without using any surfactant, templates or special equipment. Magnetite nanoflakes were precipitated from only Fe2+ chloride solution without adding Fe3+. The formation of Fe3O4 nanoflakes is suggested to occur due to formation of an intermediate goethite phase, thus providing anisotropic crystal growth. Compared to other methods, the method presented here is fast and suitable for large scale synthesis.