Study on magnetic and dielectric properties of YMnO3 ceramics

The magnetic and dielectric properties were investigated in the hexagonal YMnO3 ceramics synthesized by sol-gel method. An antiferromagnetic order about 70 K and a weak ferromagnetic order at 5 K have been detected in YMnO3 ceramics. In addition, we observed also the exchange-bias (EB) effect at low temperatures and it may originate from exchange coupling at the interface between ferromagnetic and antiferromagnetic orders for the co-existence of these two orders in some temperature region in hexagonal YMnO3. Furthermore, the dielectric measurements showed two thermally activated relaxation behaviors following the Arrhenius law in 290-430 K and above 500 K in YMnO3 ceramics and they can be explained as the dipolar effects associated with the charge carrier hopping between Mn 2+ and Mn3+ and oxygen vacancy, respectively.Department of Applied Physic