The Structure and Magnetic Properties Metal-carbon Nanocomposites NiCo / C on Based of Polyacrylonitrile

By method of IR-pyrolysis the precursor of polyacrylonitrile and compounds of cobalt and nickel metal-carbon nanocomposites were obtained, representing nanoparticles of alloy NiCo, dispersed in nanocrystal-line carbon matrix. Identification of alloy nanoparticles was carried out by the values of the lattice param e-ter, which was determined by X-ray analysis and was 0,3533 nm (values of the lattice parameter for Ni 0,3529 nm), this corresponds intermetallics Ni0,5Co0,5. By XRD analysis it was determined that an increase in the synthesis temperature of 500 to 800 ºC leads to increase in average size of coherent dissipation of crystallite metal phase. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3632

Features of Formation of the Nanoparticles of Alloys in Metal-carbon Nanocomposites FeCo / C and NiCo / C on Based Polyacrylonitrile

By the method of IR-heating the precursor on base of polyacrylonitrile, compounds of iron, cobalt and nickel metal-carbon nanocomposites were obtained, representing an ensemble of nanoparticles of intermetallic FeCo (NiCo), dispersed in nanocrystalline carbon matrix. XRD analysis revealed that the carbon structure of the PAN-based matrix changed from amorphous to nanocrystalline at the processing temperatures in the range 200-700 °C. Thus there is a reduction of metals from compounds released by degradation of the polymer with hydro-gen. FeCo alloy nanoparticles formed at synthesis temperatures T≥500 °C, in the case of nanocomposites Ni-Co / C alloy nanoparticle formation is possible at T ≥ 270 °C, which is associated with a lower temperature com-pared to the recovery of nickel from iron. According to the results of TGA and DSC found that metals are capable of initiating the chemical transformation in the PAN, resulting in reduction start temperature degradation. Ac-cording to the results of DSC revealed that the formation of nanoparticles is accompanied by release of heat due to exothermic processes occurring in the nanocomposites. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3631