Magnetic and XPS studies on RNi5 (R=La, Nd, Tb, Dy)-based compounds
Magnetic measurements and XPS studies were performed on LaNi5-xAlx, TbNi5-xAlx, DyNi5-xAlx, LaNi5-xCux and NdNi5-xCux systems. In addition, band structure calculations were also performed. The nickel moments in RNi5 (R=Nd, Tb, Dy) compounds are of ≅ 0.17 µB and ≅ 0.25 µB at 2c and 3g sites, resp...
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| Formato: | article |
| Lenguaje: | EN |
| Publicado: |
D.Ghitu Institute of Electronic Engineering and Nanotechnologies
2006
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| Materias: | |
| Acceso en línea: | https://doaj.org/article/6ab8d4b49e074356bdf9e6870980f69e |
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| Sumario: | Magnetic measurements and XPS studies were performed on LaNi5-xAlx, TbNi5-xAlx,
DyNi5-xAlx, LaNi5-xCux and NdNi5-xCux systems. In addition, band structure calculations were
also performed. The nickel moments in RNi5 (R=Nd, Tb, Dy) compounds are of ≅ 0.17 µB
and ≅ 0.25 µB at 2c and 3g sites, respectively. The nickel moments, in low temperature range,
decrease when increasing Al or Cu content and are practically nil for x > 1. The 4f-5d-3d
exchange interactions were analyzed and the contributions of local 4f-5d and short range
5d-3d exchange interactions to 5d band polarization are estimated. An effective field of the
order of (30-40) T is necessary to induce a nickel moment, at 1.7 K. Above the Curie
temperatures, the effective nickel moments were determined. The LaNi5-xCux and LaNi5-xAlx
systems, show, at T ≤ 10 K, a T2
dependence of the magnetic susceptibilities, while above a
characteristic temperature T*
, a Curie-Weiss contribution was evidenced. The magnetic
behaviour of nickel is analyzed in models, which take into account electron correlation effects
in d bands.
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