Metallic "ferroelectricity" in the pyrochlore Cd2Re2O7.

@article{Sergienko2004MetallicI,
  title={Metallic "ferroelectricity" in the pyrochlore Cd2Re2O7.},
  author={Ivan A. Sergienko and Veerle Keppens and Megan McGuire and Rongying Jin and Jian He and Stephanie Curnoe and Brian C Sales and Peter Blaha and David J. Singh and Karlheinz Schwarz and David G Mandrus},
  journal={Physical review letters},
  year={2004},
  volume={92 6},
  pages={065501}
}
A class of materials known as "ferroelectric metals" was discussed theoretically by Anderson and Blount in 1965 [Phys. Rev. Lett. 14, 217 (1965)]], but to date no examples of this class of materials have been reported. Here we present measurements of the elastic moduli of Cd2Re2O7 through the 200 K cubic-to-tetragonal phase transition. A Landau analysis of the moduli reveals that the transition is consistent with Cd2Re2O7 being classified as a ferroelectric metal in the weaker sense described… CONTINUE READING