The Formation and Study of the FeCo Nanoparticles Alloy in Structure of Metal-Carbon Nanocomposites FeCo/C

The study of the peculiarities of the formation of the nanoparticles FeCo-alloy in the composition of metal-carbon nanocomposites FeCo/C. Structure, phase composition and kinetic processes of synthesis of nanocomposites FeCo/C by methods of Mossbauer spectroscopy were studied. This allowed us to establish the peculiarities of formation of nanoparticles FeCo alloy in the composition of the nanocomposites. The nanocomposites were synthesized by the IR-pyrolysis at temperatures of precursors of 300 - 800 degrees C on the basis of polyacrylonitrile (PAN), iron acetylacetonate and cobalt acetate. Also it is established that an increase in the average size of nanoparticles FeCo with increasing temperature synthesis is occurred. In the temperature range of synthesis of 600-800 degrees C the size varies from 910 to 16-18 nm, respectively. The features the phase transitions and phase composition of the metal-carbon nanocomposites FeCo/C were studied by Mossbauer spectroscopy. Nanocomposites were synthesized in the temperature range of T = 300-800 degrees C. It was shown that the samples synthesized at T = 300 degrees C contains of superparamagnetic nanoparticles of magnetite and amorphous oxide of iron only. The process of forming nanoparticles of alloy FeCo occurs within the temperature range 500-600 degrees C due to the recovery of amorphous iron oxide and magnetite as well as them dissolving in a phase of cobalt. The growth of size of nanoparticles of alloy by agglomeration and dissolution of iron in the alloy nanoparticles occurs only at the temperature range of synthesis 600-800 degrees C. This is confirmed by a decrease of the content of Fe, which associated with carbon and it is consistent with the results of phase and structural studies, carried out in previous works.