Magneto-capacitance effect was investigated using the impedance spectroscopy
on single crystals of LuFe2O4. The intrinsic impedance response could be
separated from the interfacial response and showed a clear hysteresis loop
below TFerri ~ 240 K under the magnetic field. The neutron diffraction
experiment under the magnetic field proves the origin of dielectric property
related to the motion of nano-sized ferromagnetic domain boundary. These
results imply that the modification of the microscopic domain structure is
responsible for the magnetoelectric effect in LuFe2O4.Comment: 9 pages, 5 figure