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Properties of iron nanoparticles sealed in protective media
Schneeweiss, Oldřich ; Hapla, Miroslav ; Zbořil, R. ; Mašláň, M.
Iron nanocrystalline powder was prepared by the reduction of ferrihydride. The samples were sealed in Ar in a plastic bag to avoid any contact with air in the form of (i) the as-prepared powder, (ii) the powder mixed with a vacuum grease, and (iii) the powder after a very slow oxidation at room temperature which formed an oxidic shell. Their phase compositions were investigated by XRD and Mossbauer spectroscopy. These data were completed by magnetic measurements. The intense amorphous-like component was observed in the Mossbauer spectrum of the as-prepared powder. The origin of this component is discussed.
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Praparation, structure and properties of hybrid nanoparticles with perovskite and spinel type cores
Kaman, Ondřej ; Havlíček, David (advisor) ; Wágner, Tomáš (referee) ; Zbořil, Radek (referee)
Charles University in Prague Faculty of Science Department of Inorganic Chemistry and Academy of Sciences of the Czech Republic Institute of Physics Department of Magnetics and Superconductors ondřej Kuman Preparation, structure and properties of hybrid nanoparticles with perovskite and spinel type cores Summary oÍ Thesis Praha 2009 Introduction The presented work Preparation, stntcture- and properties of lrybrid nanoparticles withperovskite and spinel ýpe cores was primarily dedicated to the synit,esis *á .,uav of hybridmagnetic nanoparticles based on La1."Sr*Mnól perovskite phase as core material and silicashell. The motivatio^n for this topic is the chancó that the mentioned nanomaterials could beused as mediators for magnetically induced hyperthermia or at least they could show thedirection for future development of new agent inlended for magnetic hyperthermia. Moreover,it turned out that these nanoparticles are interesting as contrast agents for MRI and thereforethe sense of the intended work obtained anothei dimension. In order to achieve certaingenerality of the developed procedures. and- to _enable por.1t1" comparison oiu.q.ri." d. data,we have involved some aspects concerning the CoFezo+ andCot.*ZdF";ó;.pt"el phases. Aims of Thesis I' To study of po_ssible preparation of Lar-*sr*Mnol nanoparticles...
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Nanokrystalické částice oxidů železa, karbidů železa a alfa-Fe připravené z ferihydritu
Schneeweiss, Oldřich ; Grygar, Tomáš ; David, Bohumil ; Pizúrová, Naděžda ; Žák, Tomáš ; Zbořil, R. ; Mašláň, M.
Preparation of nanocrystalline iron oxides (hematite alpha-Fe2O3, magnetite Fe3O4), Haag carbide (Fe5C2), and alpha-Fe by thermal treatment of ferrihydrite in various atmospheres is reported. The phase composition and size of nanoparticles was controlled using the annealing temperature and atmosphere (vacuum, hydrogen, or ethylene).
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