ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
The rare earth (RE) nickel borocarbides are intermetallic layered compounds which offer the possibility to study the interplay between superconductivity and magnetism. We have doped RENi2B2C (RE=Ho,Dy,Tb) with ∼1 at. % 57Fe in order to study the magnetic phase transitions occurring in these systems by a local probe, i.e., by 57Fe Mössbauer spectroscopy. Sample characterization by x-ray diffraction as well as ac susceptibility measurements showed mainly single phase. The room temperature and 4.2 K 57Fe ME spectra essentially show one quadrupole doublet (Δ∼0.20 mm/s) for all compounds, except for RE=Tb. A magnetic hyperfine (hf) field appears in the case of RE=Tb and Ho at TN∼15 and 8 K, respectively. The magnetic hf field for Tb at 4.2 K is Bhf=0.86 T, while it is quite smaller for Ho [Bhf(5 K)∼0.30 T]. Since 57Fe at the Ni sites in RENi2B2C does not have its own magnetic moment, all magnetic hf fields are resulting from the neighboring RE moments. The absence of a hf field in DyNi2B2C at 4.2 K confirms the results from neutrons diffraction experiments: the magnetically ordered state in these two compounds is a simple collinear antiferromagnet. For Tb and Ho, however, the spin structure in the magnetically ordered state is not collinear, resulting in a transferred magnetic hf field at the 57Fe nucleus. © 1996 American Institute of Physics. [S0021-8979(96)473608-1]
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.361303
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