TY - JOUR
T1 - One-dimensional ferrimagnetic behavior of a hetero-spin chain in an organic radical crystal as probed by susceptibility and relaxation time measurements
AU - Shiomi, Daisuke
AU - Nishizawa, Masahiro
AU - Sato, Kazunobu
AU - Takui, Takeji
AU - Itoh, Koichi
AU - Sakurai, Hiromi
AU - Izuoka, Akira
AU - Sugawara, Tadashi
N1 - Funding Information:
ACKNOWLEDGMENTS The authors are grateful to Professor Kizashi Yamaguchi and Professor Wasuke Mori at Osaka University for their kind help in susceptibility measurements. This work has been supported by Grants-in-Aid for Scientific Research on Priority Area “Molecular Magnetism” (Area No. 228/04 242 103, 04 242 104 and 04 242 105) and for Encouragement of Young Scientists (No. 07740553) from the Ministry of Education, Science and Culture, Japan and also partly by the Ministry of International Trade and Industries, Japan (NED0 project on “Organic Magnets”).
PY - 1996
Y1 - 1996
N2 - Spin state energies were calculated for a linear chain composed of a doublet radical and a biradical with a triplet ground state by numerical diagonalization of finite-size Heisenberg spin Hamiltonian. When all the intermolecular antiferromagnetic interactions couple the S=1/2 sites uniformly, a ferrimagnetic-like ground state appears. This finding is consistent with the simple picture of antiparallel alignment of different S's. On the other hand, quasi-degenerate low-lying excited states appear as the spatial symmetry of intermolecular antiferromagnetic interactions is lowered. The quasi-degeneracy breaks the stability of the ferrimagnetic-like ground state. This result gives a qualitative explanation of the susceptibility and the spin-spin relaxation time measured for a nitronylnitroxide-based molecular crystal composed of an S=1/2 and S=1 molecules. The instability of the ferrimagnetic-like ground state is inherent in multi-centered antiferromagnetic interactions between the open-shell organic molecular systems, suggesting a prerequisite for purely organic ferrimagnetic ordering.
AB - Spin state energies were calculated for a linear chain composed of a doublet radical and a biradical with a triplet ground state by numerical diagonalization of finite-size Heisenberg spin Hamiltonian. When all the intermolecular antiferromagnetic interactions couple the S=1/2 sites uniformly, a ferrimagnetic-like ground state appears. This finding is consistent with the simple picture of antiparallel alignment of different S's. On the other hand, quasi-degenerate low-lying excited states appear as the spatial symmetry of intermolecular antiferromagnetic interactions is lowered. The quasi-degeneracy breaks the stability of the ferrimagnetic-like ground state. This result gives a qualitative explanation of the susceptibility and the spin-spin relaxation time measured for a nitronylnitroxide-based molecular crystal composed of an S=1/2 and S=1 molecules. The instability of the ferrimagnetic-like ground state is inherent in multi-centered antiferromagnetic interactions between the open-shell organic molecular systems, suggesting a prerequisite for purely organic ferrimagnetic ordering.
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U2 - 10.1080/10587259608033686
DO - 10.1080/10587259608033686
M3 - Article
AN - SCOPUS:4143133321
VL - 278-279
SP - 279
EP - 294
JO - Molecular Crystals and Liquid Crystals
JF - Molecular Crystals and Liquid Crystals
SN - 1542-1406
ER -