Orbital glass induced by 2D antiferromagnetic fluctuations in Eu2CuO4
Babinskii A. V. , Ginzburg S. L., Golovenchits E. I. , Sanina V. A.
A low-frequency dispersion of the permittivity which is characteristic of structural glasses [E. Courtens, Phys. Rev. В 33, 2975 (1986)] has been observed in an insulating single crystal of Eu2Cu04 in the temperature range 120-300 K. A model in which the glassy behavior arises in the orbital magnetic system of Jahn-Teller Cu2+ ions is proposed. This behavior arises because the interaction of tetragonal magnetic doublets through the 2D AFM spin subsystem is a variable-sign long-range interaction. It is suggested that this interaction leads, by virtue of a transition to chaos, to a glassy behavior even in an ordered system.