https://doi.org/10.1140/epjb/e2005-00143-2
The antiferromagnetic/paramagnetic transition in mixed-spin compounds R2BaNiO5
1
Department of Physics, University of Michigan,
Ann Arbor 48109, MI, USA
2
Institut für Theoretische Physik
J.W.G-Universität Frankfurt,
Robert-Mayer-Str. 8
60054 Frankfurt am Main, Germany
Corresponding author: a jvalvare@umich.edu
Received:
27
July
2004
Revised:
18
October
2004
Published online:
30
May
2005
We present an extensive Quantum Monte Carlo study of the magnetic properties of the mixed-spin quantum systems R2BaNiO5 (R= magnetic rare earth) which show coexistence of 3-dimensional magnetic long-range order with 1-dimensional quantum gap excitations. We discuss the validity of the performed simulations in the critical region and show the excellent agreement with experimental results. We emphasize the importance of quantum fluctuations contained in our study which is absent in previous mean-field-like treatments.
PACS: 75.10.Jm – Quantized spin models / 75.25.+z – Spin arrangements in magnetically ordered materials (including neutron and spin-polarized electron studies, synchrotron-source X-ray scattering, etc.) / 75.50.Ee – Antiferromagnetics
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2005