Effect of geometry on magnetism in small antiferromagnetic clusters

Journal Article · Fri May 01 00:00:00 EDT 1992 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.45.10103· OSTI ID:7043586

Reddy, B V; Khanna, S N ^[1]

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1. Physics Department, Virginia Commonwealth University, Richmond, Virginia 23284-2000 (United States)

The magnetic behavior of small clusters with antiferromagnetic interactions has been studied. The clusters are modeled as Ising spins located at the atomic sites, interacting via a nearest-neighbor antiferromagnetic coupling. The magnetic moments of these Ising clusters at various temperatures and magnetic fields have been calculated using Monte Carlo simulations. We have studied clusters having icosahedral and cuboctahedral arrangements and containing between 13 and 561 atoms. Our results show that the variation of magnetization with applied field and the temperature depends on the geometry of the clusters. For icosahedral clusters, the calculated behavior indicates that the clusters have free spins and behave as frustrated paramagnets. On the other hand, cuboctahedral clusters show well-defined ground states indicating that the finite size quenches the frustration inherent in the fcc lattice. We also show that the magnetization for a given cluster size depends on the cluster geometry. The theoretical predictions will be compared with recent measurements of the magnetic moment of the Cr{sub {ital n}} clusters.

• DOE Contract Number: FG05-87ER45316
• OSTI ID: 7043586
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 45:17; ISSN PRBMD; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

665000* -- Physics of Condensed Matter-- (1992-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANTIFERROMAGNETIC MATERIALS
CHROMIUM
CRYSTAL MODELS
ELEMENTS
ENERGY LEVELS
GROUND STATES
ISING MODEL
MAGNETIC MATERIALS
MAGNETIC MOMENTS
MAGNETIZATION
MATERIALS
MATHEMATICAL MODELS
METALS
TEMPERATURE EFFECTS
TRANSITION ELEMENTS