Cooperative ordering of gapped and gapless spin networks in Cu2Fe2Ge4O13.
The unusual magnetic properties of a novel low-dimensional quantum ferrimagnet Cu2Fe2Ge4O13 are studied using bulk methods, neutron diffraction, and inelastic neutron scattering. It is shown that this material can be described in terms of two low-dimensional quantum spin subsystems, one gapped and the other gapless, characterized by two distinct energy scales. Long-range magnetic ordering observed at low temperatures is a cooperative phenomenon caused by weak coupling of these two spin networks.
Condensed Matter Science Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, 37831-6393, USA. masudat@ornl.gov
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T
Masuda
A
A
Zheludev
B
B
Grenier
S
S
Imai
K
K
Uchinokura
E
E
Ressouche
S
S
Park