Synthesis and magnetic properties of novel compounds R{sub 3}(Fe,T){sub 29} (R=Y, Ce, Nd, Sm, Gd, Tb, and Dy; T=V and Cr)
- State Key Laboratory for magnetism, Institute of Physics, Chinese Academy of Sciences, Post Office Box 603, Beijing 100080, Peoples Republic of (China)
- School of Physics, The University of New South Wales, Sydney NSW 2052 (Australia)
A systematic investigation of structure and intrinsic magnetic properties of the novel compounds R{sub 3}(Fe,T){sub 29} (R=Y, Ce, Nd, Sm, Gd, Tb, and Dy; T=V and Cr) has been performed. The lattice constants and unit cell volume decrease with increasing the rare-earth atomic number from R=Nd to Dy, except for Ce, reflecting the lanthanide contraction. The Curie temperature increases from R=Ce to Gd and decreases from Gd to Dy, respectively, with increasing atomic number and Gd{sub 3}Fe{sub 29{minus}x}T{sub x} has the highest Curie temperature for each series of R{sub 3}Fe{sub 29{minus}x}T{sub x} (T=V or Cr) compounds. The saturation magnetization of R{sub 3}Fe{sub 29{minus}x}T{sub x} at 4.2 K decreases gradually from R=Nd to Dy with increasing atomic number, except for Ce, in each series of R{sub 3}Fe{sub 29{minus}x}T{sub x}. It is suggested that the Ce ion in Ce{sub 3}Fe{sub 29{minus}x}T{sub x} is valence fluctuated which leads to the unusual magnetic properties. The spin reorientations of the easy magnetization direction of R{sub 3}Fe{sub 29{minus}x}T{sub x} are observed at around 230, 230, and 160 K for R=Nd, Sm, and Tb when T=V, and at around 230 and 180 K for R=Nd and Tb when T=Cr, respectively. First order magnetization processes are observed around 5.7 T for Sm{sub 3}Fe{sub 26.7}V{sub 2.3} and 4 T for Sm{sub 3}Fe{sub 24.0}Cr{sub 5.0} at 4.2 K, 2.0 T for Tb{sub 3}Fe{sub 28.0}V{sub 1.0}, and 2.3 T for Tb{sub 3}Fe{sub 28.0}Cr{sub 1.0} at room temperature. A phenomenological analysis shows that the saturation magnetization of R{sub 3}Fe{sub 29{minus}x}T{sub x} compounds with a low T concentration can be roughly calculated based on a combination of those of the 2:17R and 1:12 units in a ratio of 1:1. {copyright} {ital 1997 American Institute of Physics.}
- OSTI ID:
- 503602
- Journal Information:
- Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 11 Vol. 81; ISSN JAPIAU; ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
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