Onset of magnetism stimulated by H absorption in UNiAl-UFeAl

0365150 - FZÚ 2012 RIV GB eng J - Journal Article
Mašková, S. - Havela, L. - Daniš, S. - Kothapalli, K. - Nasreen, F. - Andreev, Alexander V.
Onset of magnetism stimulated by H absorption in UNiAl-UFeAl.
Journal of Physics: Conference Series. Roč. 303, č. 1 (2011), 012011/1-012011/5. ISSN 1742-6588. E-ISSN 1742-6596
R&D Projects: GA ČR(CZ) GAP204/10/0330
Institutional research plan: CEZ:AV0Z10100520
Keywords : uranium intermetallics * hydrides * magnetic ordering
Subject RIV: BM - Solid Matter Physics ; Magnetism

Weak itinerant antiferromagnetism of UNiAl is rapidly suppressed by Fe doping. Magnetic order reappears as weak ferromagnetism in UNi0.75Fe0.25Al. The onset of magnetism can be shifted by H absorption. UNi0.85Fe0.15Al hydride is an antiferromagnet with TN approx. 70 K. Hydrogenating UNi0.70Fe0.30Al produces a ferromagnet (TC = 90 K). Here we describe the compound with 20% of Fe and its hydride. The proximity to magnetism shows up as non-Fermi liquid behavior, detected in specific heat as upturn, followed down to 0.3 K, which is gradually suppressed in magnetic fields of several Tesla. The hydride was found rather unstable, releasing H at ambient conditions, which made it unsuitable for the specific heat measurement. Magnetization study detected that the hydride shows up as ferromagnet TC ≈ 98 K.
Permanent Link: http://hdl.handle.net/11104/0200459