Phenomenological correlations between the occurence of different types of magnetic order, the value of the electronic specific heat divided by temperature γ*, and the shortest distance d between Ce and U atoms in a number of metallic compounds are presented. Ferromagnetism is found to occur over restricted ranges of d and γ*, and the magnetic ordering temperature Tm and the ordered moment μor are maximized for d≈4.0-4.2 Å. "Weak magnetic order", for which μor≪0.5μB, is found to occur in two distinct regimes: Large values of Tm occur for d less than the "Hill limits" d H≈3.4 Å (Ce) and 3.5 Å (U), with γ*≈3.5×104erg cm-3K-2, while very low Tm are found in several heavy fermion compounds near d≈4.15 Å and γ*≈1×105erg cm-3K-2. A plot of Tm vs. volume-scaled μor implies that metallic 4f, 5f and 3d transition metal materials can be systematically described within a unified picture. The small exchange enhancement of the magnetic susceptibility of heavy fermion compounds and the surprising trend that ferromagnetism occurs in relatively strongly hybridized systems may be explained by the wavevector dependence of the electronic self-energy that is responsible for large effective mass.
|Number of pages
|Journal of Magnetism and Magnetic Materials
|Published - Sep 1991
Bibliographical noteFunding Information:
The authors wish to thank Dr. Baird Brandow, Dr. Bobby Dunlap, Dr. Dale Koelling and Prof. Peter Riseborough for helpful discussions. Two of us (L.E.D. and J.G.H.) would like to thank the Center for Materials Science and the T-11 Group for their hospitality at Los Alamos National Laboratory where part of this work was completed. Research at the University of Kentucky was supported by a Research Opportunity Award from Research Corporation, and research at Los Alamos National Laboratory was supported by the US Department of Energy.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics