In:
Journal of Applied Physics, AIP Publishing, Vol. 50, No. B11 ( 1979-11-01), p. 7682-7686
Abstract:
Mössbauer spectroscopy has been used in a number of investigations of elemental rare earth (RE) metal and RE–transition metal intermetallic hydrides. Analysis of hyperfine parameters has established the crystalline electric field (CEF) ground state for Dy3+ in DyH2 and for Er3+ in ErH2 and YH2. In all cases the results are compatible with the presence of negatively charged hydrogen atoms. Long range magnetic ordering is observed in the RE-H2 compounds. In DyH2, short-range magnetic ordering is seen at temperatures up to twice the long-range transition temperature. This arises from the changes in CEF symmetry due to the presence of a few H atoms which are not in regular tetrahedral sites. These effects are much more pronounced in slightly non-stoichiometric compounds and can result in dramatic changes in the magnetic ordering temperature. As an example of an intermetallic hydride, we have studied the cubic Laves phase RE-iron compounds. These form several stable hydride phases RE-Fe2Hx, with the maximum x being in excess of 4. The magnetic transition temperatures decrease to roughly half their original values for x=3.5, and the RE-Fe exchange interaction is weakened. For x=4, a sharp reduction in both the Fe magnetic moment and the magnetic ordering temperature occurs.
Type of Medium:
Online Resource
ISSN:
0021-8979
,
1089-7550
Language:
English
Publisher:
AIP Publishing
Publication Date:
1979
detail.hit.zdb_id:
220641-9
detail.hit.zdb_id:
3112-4
detail.hit.zdb_id:
1476463-5
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