Relaxor ferroelectric behavior of BaMnO3 (2H) at room temperature

Geometrically frustrated hexagonal BaMnO3 (2H) is an interesting material due to the presence of more than one ferroic order parameters. Although the material is well known, still there exists confusion on the crystal structure of this material at room temperature and its ferroelectric properties have not been explored. Here, we report noncentrosymmetric crystal structure and ferroelectric properties of BaMnO3 (2H) at room temperature. The dielectric diffusivity calculated from modified Curie-Weiss laws and non linear Vogel-Fulcher fittings implies weak relaxor characteristic of BaMnO3 (2H). The ferroelectric properties arise due to off centering of Mn4+ ion in unit cell and weak relaxor properties are attributed to the presence of a smaller amount of Mn3+ cations which creates disorder in 2H-BaMnO3. (C) 2012 American Institute of Physics. [doi:10.1063/1.3679176]