Competing spin phases in geometrically frustrated magnetic molecules
Autor(en): | Schroder, C Nojiri, H Schnack, J Hage, P Luban, M Kogerler, P |
Stichwörter: | ANTIFERROMAGNET; FIELD; LATTICE; Physics; Physics, Multidisciplinary; SPHERES; STATE | Erscheinungsdatum: | 2005 | Herausgeber: | AMERICAN PHYSICAL SOC | Journal: | PHYSICAL REVIEW LETTERS | Volumen: | 94 | Ausgabe: | 1 | Zusammenfassung: | We identify a class of zero-dimensional classical and quantum Heisenberg spin systems exhibiting anomalous behavior in an external magnetic field B similar to that found for the geometrically frustrated kagome lattice of classical spins. Our calculations for the isotropic Heisenberg model show the emergence of a pronounced minimum in the differential susceptibility dM/dB at B-sat/3 as the temperature T is raised from 0 K for structures based on corner-sharing triangles, specifically the octahedron, cuboctahedron, and icosidodecahedron. As the first experimental evidence we note that the giant Keplerate magnetic molecule {Mo72Fe30} (Fe3+ ions on the 30 vertices of an icosidodecahedron) exhibits this behavior. For low T when Bapproximate toB(sat)/3 two competing families of spin configurations exist of which one behaves magnetically ``stiff'' leading to a reduction of dM/dB. |
ISSN: | 00319007 | DOI: | 10.1103/PhysRevLett.94.017205 |
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geprüft am 20.05.2024