Coercivity and spin reorientation transitions in Nd-Fe-B nanocomposites prepared by melt spinning
- Vienna Univ. of Technology (Austria). Inst. for Experimental Physics
- Univ. of Sheffield (United Kingdom). Dept. of Engineering Materials
- Saitama Univ., Urawa (Japan). Dept. of Material Sciences
Alloys of composition Nd{sub 9}Fe{sub 85}B{sub 6}, Nd{sub 11.76}Fe{sub 82.46}B{sub 5.88}, and Nd{sub 18}Fe{sub 76}B{sub 6} were prepared by melt spinning at roll velocities from 19 to 25 m/s. The grain size distribution of rapidly quenched flakes were evaluated by means of X-ray diffraction line broadening. The average grain size of rapidly quenched Nd-Fe-B alloys is within a range from 19 to 40 nanometers and differs from the roll contact side to the free side of the flakes. For the first time, the spin reorientation transitions T{sub sr} of nanophase Nd{sub 2}Fe{sub 14}B alloys have been determined. They were found to be lower than that of bulk Nd{sub 2}Fe{sub 14}B. The smaller the grain size, the lower is T{sub sr}. Also for the first time, the temperature dependence of the coercivity of nanophase Nd-Fe-B magnets was determined from 4.2 to 300 K by measuring hysteresis loops on a single flake in a pulsed-field magnetometer with a field strength up to 24 MA/m. The coercivity of the nanophase Nd-Fe-B has less of a temperature dependence than sintered magnets.
- Sponsoring Organization:
- Fonds zur Foerderung der Wissenschaftlichen Forschung, Wien (Austria)
- OSTI ID:
- 509275
- Journal Information:
- IEEE Transactions on Magnetics, Vol. 33, Issue 3; Other Information: DN: Presented at the 1996 international magnetics conference, April 9--12, 1996, Seattle, WA (US); PBD: May 1997
- Country of Publication:
- United States
- Language:
- English
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