Hughes, I. D., Daene, M., Ernst, A., Hergert, W., Lueders, M., Poulter, J., Staunton, J. B., Svane, A., Szotek, Z. and Temmerman, W. M.. (2007) Lanthanide contraction and magnetism in the heavy rare earth elements. Nature, Vol.446 (No.7136). pp. 650-653. ISSN 0028-0836

Full text not available from this repository.

Abstract

The heavy rare earth elements crystallize into hexagonally close packed ( h. c. p.) structures and share a common outer electronic configuration, differing only in the number of 4f electrons they have(1). These chemically inert 4f electrons set up localized magnetic moments, which are coupled via an indirect exchange interaction involving the conduction electrons. This leads to the formation of a wide variety of magnetic structures, the periodicities of which are often incommensurate with the underlying crystal lattice(2). Such incommensurate ordering is associated with a 'webbed' topology(3,4) of the momentum space surface separating the occupied and unoccupied electron states ( the Fermi surface). The shape of this surface - and hence the magnetic structure - for the heavy rare earth elements is known to depend on the ratio of the interplanar spacing c and the interatomic, intraplanar spacing a of the h. c. p. lattice(5). A theoretical understanding of this problem is, however, far from complete. Here, using gadolinium as a prototype for all the heavy rare earth elements, we generate a unified magnetic phase diagram, which unequivocally links the magnetic structures of the heavy rare earths to their lattice parameters. In addition to verifying the importance of the c/a ratio, we find that the atomic unit cell volume plays a separate, distinct role in determining the magnetic properties: we show that the trend from ferromagnetism to incommensurate ordering as atomic number increases is connected to the concomitant decrease in unit cell volume. This volume decrease occurs because of the so-called lanthanide contraction(6), where the addition of electrons to the poorly shielding 4f orbitals leads to an increase in effective nuclear charge and, correspondingly, a decrease in ionic radii.

Item Type:	Journal Article
Subjects:	Q Science
Divisions:	Faculty of Science > Physics
Journal or Publication Title:	Nature
Publisher:	Nature Publishing
ISSN:	0028-0836
Date:	5 April 2007
Volume:	Vol.446
Number:	No.7136
Number of Pages:	4
Page Range:	pp. 650-653
Identification Number:	10.1038/nature05668
Status:	Peer Reviewed
Publication Status:	Published
Access rights to Published version:	Restricted or Subscription Access
URI:	http://wrap.warwick.ac.uk/id/eprint/32249

Data sourced from Thomson Reuters' Web of Knowledge

Request changes to a record

Actions (login required)

View Item