Dielectric anomaly at TN in LaMnO3 as a signature of coupling between spin and orbital degrees of freedom

We observe a distinct anomaly in dielectric permittivity (epsilon(')) as well as relaxation time (tau(0)) versus temperature (T) pattern at the antiferromagnetic transition point T-N in a single crystal of LaMnO3. The equivalent circuit analysis of the impedance spectra across T-N reveals a clear anomaly in the capacitive component C-0 at T-N. Since no structural transition takes place across T-N, the anomaly in tau(0) and C-0 at T-N possibly signifies multiferroicity stemming from coupling between orbital and spin order in LaMnO3.