Mössbauer Spectroscopy On Selectred Magnetic Compounds

The applications of magnetic materials are related to their magnetic and crystal structure as well as electronic properties. In this thesis, mainly experimental methods have been focussed on novel materials and bulk materials. A selection of materials were studied by several techniques like Mössbauer spectroscopy, X-ray and neutron diffraction and magnetisation measurements. New technology allow us to prepare artificial materials with unic magnetic properties. Magnetic multilayers are very interesting not only from phenomenological point of view but also as good applications materials. In this work will be shown some results from Fe/V and Fe/Co multilayer system The (Fe1-xMnx)3P system has been studied at both ends of the composition range. At the Fe-rich end, compounds exhibiting ferromagnetic ordering are formed, while at the Mn-rich end, an antiferromagnetic coupling was discovered. The experimental results are supported by theoretical calculations. Rare-earth compounds with focus on Fe0.65Er0.2B0.15 were studied by means of traditional Mössbauer spectroscopy, Monochromatic Circular Polarized Mössbauer Spectroscopy, X-ray diffraction and magnetic mesurements. This compound shows interesting behaviour of Fe magnetic moment at low and room temperature. The first magnetic studies on rhombohedral Li3Fe2(PO4)3 at low temperature has also been made and an antiferromagnetic structure was revealed

Studies of the Magnetite Nanoparticles by Means of Mössbauer Spectroscopy

The magnetite nanoparticles were prepared by modified Massart's method in water and in alcohol. The influence of the condition of preparation on the properties of magnetite nanoparticles were investigated by Mössbauer spectroscopy. The size of the particles were determined by transmission electron microscopy. It was shown that the particles size in the alcoholic reaction is smaller than in aqueous reaction. Moreover, the increase in the reaction time improves the stoichiometry of magnetite nanoparticles

Chemical preparation of core - shell nanoparticles

Nanoparticles obtained during layer-by-layer chemical deposition have been obtained. The particles diameter varied between 5 nm and 9 nm and can be tuned by changing molarity of the synthesis ingredients. The intention was the creation of copper or iron oxide layer during the process. Layer composition were changed using Cu rich or Fe rich ingredients. Magnetic properties of the particles strongly depend on the composition of covered material, indicating for their core-shell structure

Mössbauer Studies of Core-Shell Nanoparticles.

The ferrite magnetic nanoparticles with core-shell structures were obtained in two step preparation process. The Mössbauer spectra obtained for particles of pure maghemite or magnetite and two layered core-shell one the magnetite on maghemite and maghemite on magnetite are very different from each other. The presented results show that interparticle and intraparticle interaction plays important role in overall magnetic properties as well

Mössbauer Studies of Core-Shell Nanoparticles.

The ferrite magnetic nanoparticles with core-shell structures were obtained in two step preparation process. The Mössbauer spectra obtained for particles of pure maghemite or magnetite and two layered core-shell one the magnetite on maghemite and maghemite on magnetite are very different from each other. The presented results show that interparticle and intraparticle interaction plays important role in overall magnetic properties as well

Nanoparticle morphology and magnetic properties modified by synthesis conditions

In this paper, we present a comparative analysis of the physicochemical properties of magnetite nanoparticles synthesized via two primary methods: (i) co-precipitation of iron (II) and (III) chloride in an ammonia solution and (ii) thermal decomposition of Fe(acac)3 in an organic solvent. In each case, variable synthesis conditions were used (mixing, temperature, inert gas presence, time of synthesis), which significantly influenced the resulting nanoparticle characteristics, including size, size distribution, shape, and magnetic properties. By utilization of such techniques as transmission electron microscopy, X-ray diffraction, infrared spectroscopy, and Mössbauer spectroscopy, we demonstrate the ability to exert control over particle growth to a considerable extent. Our findings underscore the innovative aspect of our work, revealing quantitative insights into the precise manipulation of nanoparticle properties, thus offering promising ways for tailored applications in diverse fields

Structure of Iron Ions in Some Acetone Based Electrolytes

X-ray absorption, Mössbauer, and Raman spectroscopy were combined to determine the local environment of iron ions in acetone based solutions of FeCl2. It is shown that part of the Fe(II) ions change their oxidation state, accompanied by symmetry change from octahedral Fe(H2O)6(2+) to tetrahedral [FeCl4](-) at large acetone concentrations. The ratio of Fe(II)/Fe(III) determined by Mössbauer spectroscopy agrees well with that determined by the X-ray absorption studies. Raman measurements confirm quantitative estimations of [FeCl4](-) species in acetone rich solutions