ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
Heavy fermion itinerant antiferromagnetic UNiAl is one of the very few U-containing compounds which absorbs H2/D2 without disproportionation. The present neutron diffraction studies on UNiAlDy (y=2.2) are directed towards resolving controversies with regard to the occupancy of Ni atoms and the associated interstitial sites for (H/D) atoms, as well as the nature of magnetic ordering in the higher hydride phase with y≥2. The fit to the neutron diffraction data is found to improve considerably if the Ni atoms originally lying in the U-atoms' plane in UNiAl get shifted to the Ni–Al atoms' plane in the deuteride. This is in agreement with an earlier neutron diffraction report on a deuteride sample of similar composition [T. Yamamoto et al., J. Alloys Compd. 269, 162 (1998)] and our x-ray structural studies on UNiAlH2.3 [P. Raj et al., Phys. Rev. B 63, 94414 (2001)], but differs from those of Bordallo et al., [H. N. Bordallo et al., Physica B 276–278, 706 (2000)] and of Kolomiets et al. [A. V. Kolomiets et al., J. Appl. Phys. 87, 6815 (2000)]. Our values of the structural parameters including the D-site occupancies are broadly in agreement with the results of Yamamoto et al. The magnetization studies on UNiAlD2.2 show a single antiferromagnetic transition with Néel temperature, TN=95 K. © 2001 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.1361262
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