Dielectric anomaly at T_N in LaMnO3

TL;DR

This study reports a dielectric anomaly at the antiferromagnetic transition temperature in LaMnO3, suggesting potential multiferroic behavior due to coupling between orbital and spin orders.

Contribution

It provides evidence of dielectric anomalies at T_N in LaMnO3 without structural changes, indicating possible multiferroicity from orbital-spin coupling.

Findings

Dielectric permittivity shows a distinct anomaly at T_N.

Capacitive component C_0 exhibits anomaly at T_N.

No structural transition occurs across T_N.

Abstract

We observe a distinct anomaly in dielectric permittivity (epsilon') as well as relaxation time (tao_0) versus temperature (T) pattern at the antiferromagnetic transition point (T_N) in single crystal of LaMnO3. The equivalent circuit analysis of the impedance spectra across T_N reveals clear anomaly in the capacitive component C_0 at T_N. Since no structural transition takes place across T_N, the anomaly in tao_0 and C_0 at T_N possibly signifies multiferroicity stemming from coupling between orbital and spin order in LaMnO3.