ISSN:
1089-7550
Quelle:
AIP Digital Archive
Thema:
Physik
Notizen:
Alloys with the composition Nd2(Fe,Ti)19 can exist in two crystal structures depending on the preparation technique. Melt-spun material has a hexagonal TbCu7-type structure (a=4.902 A(ring), c=4.248 A(ring)) for a range of quenching speeds. Alloys prepared by arc melting, annealing at 1373 K and then water quenching have a complex monoclinic structure derived from a TbCu7 superlattice (a=10.644 A(ring), b=8.585 A(ring), c=9.755 A(ring), β=96.92°) and related to those of other intermetallics such as tetragonal Nd(Fe,Ti)12 and rhombohedral Nd2Fe17. Magnetic ordering temperatures for annealed (monoclinic) and melt-spun (hexagonal) Nd2(Fe,Ti)19 are 411 and 454 K, respectively. 57Fe Mössbauer spectroscopy at 295 K demonstrates that the local environments of the Fe atoms in the two structural modifications of Nd2(Fe,Ti)19 are similar. The average 57Fe magnetic hyperfine fields at 295 K for the monoclinic and hexagonal Nd2(Fe,Ti)19 are 20.8 and 22.3 T, corresponding to average Fe magnetic moments of 1.33 and 1.43μB, respectively.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1063/1.356696
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