Approaching the Ground State of the Kagome Antiferromagnet

Journal Article · Fri Feb 09 04:00:00 EST 2007 · Physical Review Letters

DOI:https://doi.org/10.1103/PHYSREVLETT.98.067201· OSTI ID:20955453

Schweika, W ^[1]; Valldor, M; Lemmens, P ^[2]

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1. Institut fuer Festkoerperforschung, Forschungszentrum Juelich, D-52425 Juelich (Germany)
2. Physik der Kondensierten Materie, TU-Braunschweig, D-38106 Braunschweig (Germany)

Y{sub 0.5}Ca{sub 0.5}BaCo{sub 4}O{sub 7} contains kagome layers of Co ions, whose spins are strongly coupled, with a Curie-Weiss temperature of -2200 K. At low temperature, T=1.2 K, our diffuse neutron scattering study with polarization analysis reveals characteristic spin correlations close to a predicted two-dimensional coplanar ground state with staggered chirality. The absence of three-dimensional long-range antiferromagnetic order indicates negligible coupling between the kagome layers. The scattering intensities are consistent with high spin S=3/2 states of Co{sup 2+} in the kagome layers and low spin S=0 states for Co{sup 3+} ions on interlayer sites. Our observations agree with previous Monte Carlo simulations indicating a ground state of effectively short range, staggered chiral spin order.

• OSTI ID: 20955453
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 6 Vol. 98; ISSN 0031-9007; ISSN PRLTAO
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ANTIFERROMAGNETISM
BARIUM COMPOUNDS
CALCIUM COMPOUNDS
CHIRALITY
COBALT IONS
COBALT OXIDES
COMPUTERIZED SIMULATION
CURIE-WEISS LAW
GROUND STATES
LAYERS
MONTE CARLO METHOD
NEUTRON DIFFRACTION
POLARIZATION
SPIN
TEMPERATURE RANGE 0000-0013 K
THREE-DIMENSIONAL CALCULATIONS
TWO-DIMENSIONAL CALCULATIONS
YTTRIUM COMPOUNDS