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Information × Registration Number 0221U106154, 0119U102328 , R & D reports Title Receiving nanopowders with better magnetic properties based on Fe oxides woth cations Co2+, Cu2+, Zn2+ and Ni2+ popup.stage_title Head Pavlenko Olesya Yu., Registration Date 28-10-2021 Organization Institute of Problems of Materials Science named after IM Frantsevich of the National Academy of Sciences of Ukraine popup.description2   Determination of the single colloid-chemical mechanism of the formation of nanosized spinel ferrite particles when the rotation-corrosion dispergation (RCD) method, performed in the open-air system in the presence of iron (steel), was applied has been found as the main result of the present work. It lied in the interaction of the products of Fe(II)-Fe(III) layered double hydroxide (LDH) dissolution with transition 3d-metal aquahydroxoforms. The anion composition of the dispersion medium influences the phase composition of the mineral mixtures formed under the RCD conditions. It was shown that the usage of cobalt, zinc, nickel or copper chloride and sulfate solutions causes to the appearance of the mixtures containing spinel ferrite and oxyhydroxides, in the first case, and Me(II)-Fe(II/III) LDH included corresponding anions, in the second case. The performing of the phase formation process in the chloride-containing solutions results in the homogenization of the mixtures under calcination temperature 300-400 °С, whereas the usage of chloride-containing solutions involves increase in calcination Т up to 900-1100 °С. At the same time, the formation of the homogeneous spinel ferrite particles at T < 50 °С takes place in the presence of nitrate-containing water solutions. It was firstly determined the key role of cation composition of the dispersion medium where the RCD procedure was performed in a way of the fixation of 3d-metal cations by the spinel ferrite phases. Whereas the Co2+ and Ni2+ cations are included into spinel ferrite structure, cations Cu2+ and Zn2+ diffuse to the iron oxide’s surface at the time their thermal transformation. Such kind of cations is desorbed from the oxide’s surface when iron oxide phase brings into the contact with chloride acid solutions or organic liquids containing oleic acid. Moreover, the cation’s nature determines the magnetic properties of the initial oxide-hydroxide mixtures and the products of their thermal homogenization a Product Description popup.authors popup.nrat_date 2021-10-28 Close