Sonochemical preparation of nanosized amorphous Fe-Ni alloys
نویسندگان
چکیده
Nanosized amorphous alloy powders of Fe20Ni80 , Fe40Ni60 , and Fe60Ni40 were prepared by sonochemical decomposition of solutions of volatile organic precursors, Fe~CO!5 and Ni~CO!4 in decalin, under an argon pressure of 100 to 150 kPa at 273 K. Magnetic susceptibility of Fe40Ni60 and Fe60Ni40 indicates blocking temperatures of 35 K and a magnetic particle size of about 6 nm. Thermogravimetric measurements of Fe20Ni80 give Curie temperatures of 322 °C for amorphous and 550 °C for crystallized forms. Differential scanning calorimetry exhibits an endothermic transition at 335 °C from a combination of the magnetic phase transition and alloy crystallization. The Mössbauer spectrum of crystallized Fe20Ni80 shows a sextet pattern with a hyperfine field of 25.04 T. © 1997 American Institute of Physics. @S0021-8979~97!06310-X#
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