The Formation of Structure and Phase Composition and Magnetic Properties of-Fe(Fe_3C, Fe_5SiC)-SiO_2 Nanocomposites upon Mechanical Alloying

摘要

Structural and phase transformations that occur in Fe(Fe_3C, Fe_3SiC)—SiO_2 (amorphous quartz) systems during mechanical alloying in an Ar atmosphere and in air have been studied by X-ray diffraction, Mossbauer spectroscopy, IR spectroscopy, electron microscopy, and magnetometry. It has been shown that the mechanoactivation treatment leads to the formation of isolated particles 2-20 nm in size with a complex phase composition (Fe, FeSi alloy, oxides, silicates, and carbides), which depends on the milling atmosphere. It has been found out that the magnetic properties of such systems strongly depend on the oxygen and carbon compounds existing in the system, which cannot be detected by X- ray diffraction, but their presence is testi-fied by the data of Mossbauer spectroscopy.