Field-induced reentrant novel phase and a ferroelectric-magnetic order coupling in HoMnO3.
A reentrant novel phase is observed in the hexagonal ferroelectric HoMnO3 in the presence of magnetic fields in the temperature range defined by a plateau of the dielectric constant anomaly. The plateau evolves with fields from a narrow dielectric peak at the Mn-spin rotation transition at 32.8 K in zero field. The anomaly appears both as a function of temperature and as a function of magnetic field without detectable hysteresis. This is attributed to the indirect coupling between the ferroelectric (FE) and antiferromagnetic (AFM) orders, arising from an FE-AFM domain wall effect.
Department of Physics and TCSAM, University of Houston, Houston, Texas 77204-5002, USA.
B
B
Lorenz
A P
AP
Litvinchuk
M M
MM
Gospodinov
C W
CW
Chu