Low temperature phenomena in ferroic BiMO3-PbTiO3 (M: Mn and Sc)

Low temperature, reversible mechanical effects in BiMnO3-PbTiO3 are shown to be analogous to those reported in multiferroic BiFeO3. The same stiffening (on cooling) has been found in ferroelectric BiScO3-PbTiO3 that shows negligible conduction. This has allowed permittivity and polarization studies, not possible in BiMnO3-PbTiO3, to be accomplished. Results indicate mechanical effects to be associated with a phase transition, most probably governed by an order parameter other than electric polarization, but to which it is coupled. The possibility of a common origin for the effects in the three Bi-containing perovskites is discussed, along with implications on the multiferroicity of BiMnO3-PbTiO3. (C) 2011 American Institute of Physics. [doi:10.1063/1.3591176]