Abstract
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.
Recommended Citation
P. Raj et al., "Structure and Magnetic Studies on UNiAlD2.2," Journal of Applied Physics, vol. 89, no. 11 II, pp. 7192 - 7194, American Institute of Physics, Jun 2001.
The definitive version is available at https://doi.org/10.1063/1.1361262
Department(s)
Physics
Publication Status
Available Access
International Standard Serial Number (ISSN)
0021-8979
Document Type
Article - Journal
Document Version
Final Version
File Type
text
Language(s)
English
Rights
© 2024 American Institute of Physics, All rights reserved.
Publication Date
01 Jun 2001
