https://doi.org/10.1140/epjb/e2002-00400-x
Ferrimagnetic ground state of a phenylene polymer with organic radicals
1
Department of Physics, Wuhan University, Wuhan 430072, PR China
2
Department of Physics, Huazhong University of Science and Technology,
Wuhan 430074, PR China
Corresponding author: a wzwang70@hotmail.com
Received:
15
July
2002
Published online:
31
December
2002
A ferrimagnetic polymer with m-phenylene skeleton as coupling unit is studied with the Hubbard model in the self-consistent mean-field theory. The ferrimagnetic ground state with a total spin S=1 per unit cell is obtained and originates from the antiferromagnetic correlations between the nearest neighbors. If the on-site electron-electron repulsions at the radical sites and at the phenylene ring sites are different, the gap in energy band structure may disappear and the ferrimagnetic ground state becomes unstable. The charge density and spin density can transfer between the radical sites and the phenylene ring sites due to the competition between the hopping integral and the on-site repulsion at different sites.
PACS: 71.27.+a – Strongly correlated electron systems; heavy fermions / 71.10.Fd – Lattice fermion models (Hubbard model, etc.) / 75.30.Fv – Spin-density waves
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2002
