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The ferromagnetic Fe-based amorphous alloys were studied due to properties for soft magnetic applications. Depending on different Nb addition, the formation of crystalline phases after annealing of amorphous Fe80-xB20Nbx (x = 4, 6, 10) alloys was studied. The crystallization products as well as the phase structure were determined using the Mössbauer spectrometry combined with differential scanning calorimetry and magnetic measurements. The addition of Nb caused a shift of crystallization process towards higher temperatures and induced changes in coercive force and decreased the saturation magnetization. It was found that Nb addition changed the crystallization process from single crystallization for Fe76B20Nb4 alloy to binary crystallization in the Fe74B20Nb6 and Fe70B20Nb10 glasses. The annealing process at the onset crystallization temperature induced complex phase formation including the α-Fe, Fe3B, and Fe2B phases for alloys x = 4, 6. [ABSTRACT FROM AUTHOR]

The Pechini sol-gel method was applied to obtain LiMn2-xTxO4 (T = Ni, Fe; x = 0.1 to 0.5) nanopowders. Crystal and electronic structures, chemical composition and magnetic properties of the materials were characterized by X-ray diffraction, XPS, SEM/EDX microscopy, prompt gamma-ray activation analysis (PGAA), Mössbauer spectroscopy and magnetic susceptibility, respectively. XRD measurements showed that the LiMn2-xNixO4 were single phase for x = 0.1 and 0.2. Three samples with higher Ni content contained some addition of a second phase. Analysis of the oxidation state of the dopants by XPS revealed ionic Ni2+ and Fe3+. Mössbauer spectroscopy also confirmed 3+ oxidation state of iron and its location in octahedral sites, which excluded the inverse spinel configuration. XPS examinations showed that Mn3+ ions dominated in the iron substituted series whereas the Mn4+ was dominant in the nickel series. [ABSTRACT FROM AUTHOR]

The paper presents the structural analysis of Fe62-xCoxNb8B30 metallic glasses (x = 0, 20) in as-cast and after crystallization state. The studies were performed on metallic glasses of ribbon form with thickness of 0.05 and 0.06 mm. The structure analysis of the samples in as-cast state and phase analysis of studied alloys after annealing was carried out by the X-ray diffraction methods. Moreover, the Mössbauer spectroscopy was also used to investigate the local structure for examined alloys. The soft magnetic properties examination covered the initial magnetic permeability. The after-effects of magnetic permeability were also conducted. [ABSTRACT FROM AUTHOR]

Fe-based nanocrystalline alloys were prepared by the melt-spinning technique and characterized by X-ray diffraction, magnetostatic and Mössbauer effect methods. The Mössbauer spectroscopy allows to study the local environment of the Fe atoms in the investigated Fe80-xNixB20 (x = 8, 16, 24, 28) compounds and showing the changes in the structure due to the changing of Ni addition. Combination of X-ray diffraction and Mössbauer spectroscopy results confirm formation of different number of phase complex, including the γ-FeNi, -FeNi, FeB, Fe2B, Fe3B in the investigated materials together with increase of Ni content. [ABSTRACT FROM AUTHOR]

The structural and magnetic properties of rare earth iron intermetallic compounds TbGdFe and YGdFe ( x = 0. 0, 0. 1, 0. 2, 0. 4, 0. 5, 0. 6, 0. 8, 1. 0) was studied by X-ray diffraction, the Fe Mössbauer effect and SQUID measurements. All investigated compounds crystallize in the rhombohedral PuNi3-type of crystal structure. The investigation of magnetic properties of RGdFe proved their ferrimagnetic behavior. The Curie temperature of the investigated compounds decreases with the increase of R concentration from 721K (GdFe) to 655K (TbFe) and 533K (YFe). The saturation magnetic moment MS in the RGd Fe system increase with x parameter. The Mössbauer spectra are analyzed using four sextets, corresponding to three crystallographically (b, c, h) and four magnetically (b, c, h, h) inequivalent sites for iron. The mean hyperfine magnetic field increases with increase of the Gd concentration [ABSTRACT FROM AUTHOR]