Measurements of the pressure and magnetic field dependence of multiferroic DyMn2O5

Abstract

We have studied the temperature (T) dependence of the dielectric constant of multiferroic DyMn2O5 under magnetic field (H) and pressure (P) to map out a complete T-H-P phase diagram. Our epsilon(T,H,P) data show that most of the phase transitions are rather insensitive to applied field and pressures, except for the two phase transitions seen near 27 and 18 K, respectively. These two transitions appear to merge into one transition above 12 T, and this critical field moves toward lower magnetic fields upon application of external pressure. We also found that there is significant magnetoelectric effect right up to 17 T. We will discuss our findings in light of the intricate interplay of many degrees of freedom in this interesting system.