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The methods of X ray diffraction, Mössbauer spectroscopy, IR spectroscopy, and laser diffracto metry are employed to study the changes in the structure and phase transformations that accompany mechanical alloying of Si and 57 Fe used in an atomic ratio of 99 : 1. It is established that the process comprises the development of a nanocrystalline state of Si with crystallite sizes smaller than 10 nm; the formation of an amorphous phase of Si at particle surfaces and in near boundary distorted zones of interfaces in Si nanostruc ture; the penetration of 57 Fe atoms along grain boundaries; and the formation of Si-Fe clusters, the local environment of Fe atoms in which is typical of a deformed α FeSi 2 phase, with these clusters being located in the interfaces.

The electronic structure of 16 complex compounds of RE (Y, La–Tb) with the same ligand – nitrilotris(methylenephosphonic acid) [NTP, N(CH2PO3)3H6] and with different coordination symmetries of the RE atom is investigated. The structure of XP‐spectra of a valence band in this area significantly differs for structures with non‐octahedral O‐coordination of the RE atom, on the one hand, and those with pseudo‐octahedral O‐coordination of the RE atom, on the other hand. In the XP‐spectra of non‐octahedral O‐coordination complexes the O2s‐states have a maximum at EB = 24–26 eV and are poorly overlapped with Ln5p‐states. For pseudo‐octahedral O‐coordination structures a wide strip is observed in the field of EB = 20–28 eV corresponding to an overlap M5p‐ and O2s‐states with formation of internal valence molecular orbitals (IVMO). Apparently, in pseudo‐octahedral O‐coordination structures the arrangement of O atoms agrees with the octahedral symmetry of RE p‐orbitals and leads to the formation of IVMO M5p+O2s.

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X-ray diffraction, magnetic measurements and Mössbauer spectroscopy were used to study magnetic properties and hyperfine interaction parameters of nanocrystalline (< 10 nm) and bulk bcc Fe, Fe90Ge10, and Fe77Al23 alloys. It has been established that nanocrystalline state does not influence the formation of specific saturation magnetization, Curie temperature, isomer shift and hyperfine magnetic field. No additional sextets in Mössbauer spectra as well as special features in temperature dependences of a.c. magnetic susceptibility have been found. A slight increase (∼ 20%) of the width of the nanocrystalline Fe Mössbauer spectral lines has been observed.PACS : 75.50.Bb