We report on the high pressure synthesis of BiMn7O12, a manganite displaying a "quadruple perovskite" structure. Structural characterization of single crystal samples shows a distorted and asymmetrical coordination around the Bi atom, due to presence of the 6s2 lone pair, resulting in non-centrosymmetric space group Im, leading to a permanent electrical dipole moment and ferroelectric properties. On the other hand, magnetic characterization reveals antiferromagnetic transitions, in agreement with the isostructural compounds, thus evidencing two intrinsic properties that make BiMn7O12 a promising multiferroic material.
Cite
@article{arxiv.0810.0667,
title = {Synthesis and characterization of multiferroic BiMn$_7$O$_{12}$},
author = {F. Mezzadri and G. Calestani and M. Calicchio and E. Gilioli and F. Bolzoni and R. Cabassi and M. Marezio and A. Migliori},
journal= {arXiv preprint arXiv:0810.0667},
year = {2009}
}