Properties and structure of ultrafine amorphous Fe-Ni-B powder obtained by borohydride reduction
- Shanghai Iron and Steel Research Inst. (China)
Ultrafine amorphous Fe-Ni-B powders were prepared by borohydride reduction, and their properties and structure were investigated by extended x-ray absorption fine structure (EXAFS), x-ray photoelectron spectroscopy (XPS), small-angle x-ray scattering (SAXS), Moessbauer spectra, transmission electron microscopy (TEM), differential scanning calorimetry (DSC), etc. The SAXS results for Fe{sub 48}Ni{sub 21}B{sub 31} powders reveal the particle size statistic distribution, which is 1.7 nm, 80%; 6.4 nm, 8%; and 15.3 nm, 12%. TEM micrographs demonstrate the aggregates with fractal dimension of 1.5. The short-range order parameters of Fe{sub 48}Ni{sub 21}B{sub 31} powders are obtained from EXAFS measurement. The XPS studies reveal that the higher H{sub c} values of the powder prepared at higher reaction temperature relate to the appearance of the satellite structure at about 715.6 eV, which is characteristic for iron oxides, FeO/Fe{sub x}O. This new interesting finding has been explained by the lattice misfit on the interface between the matrix and oxides, based on EXAFS studies. The crystalline behavior and magnetic properties demonstrate that there is no significant difference in amorphous structure between the chemically synthesized powders and melt-spun ribbons. However, the reasonable prediction of difference of amorphous structure and its formation mechanism between them has been proved by the XPS depth profile of Fe{sub 48}Ni{sub 21}B{sub 31} powders, exhibiting considerable surface enrichment of boron and nickel, and EXAFS studies, showing a stronger interaction between nearer neighbors in the powders.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 105923
- Journal Information:
- Journal of Materials Engineering and Performance, Journal Name: Journal of Materials Engineering and Performance Journal Issue: 4 Vol. 4; ISSN 1059-9495; ISSN JMEPEG
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
AMORPHOUS STATE
BORON ALLOYS
BORON COMPOUNDS
CALORIMETRY
EXPERIMENTAL DATA
IRON ALLOYS
IRON SULFATES
MAGNETIC PROPERTIES
MICROSTRUCTURE
NICKEL ALLOYS
NICKEL CHLORIDES
PHOTOELECTRON SPECTROSCOPY
POTASSIUM HYDRIDES
SMALL ANGLE SCATTERING
SODIUM HYDRIDES
SYNTHESIS
TRANSMISSION ELECTRON MICROSCOPY