Emergent room temperature polar phase in CaTiO 3 nanoparticles and single crystals

Mariola O. Ramirez, Tom T.A. Lummen, Irene Carrasco, Eftihia Barnes, Ulrich Aschauer, Dagmara Stefanska, Arnab Sen Gupta, Carmen De Las Heras, Hirofumi Akamatsu, Martin Holt, Pablo Molina, Andrew Barnes, Ryan C. Haislmaier, Przemyslaw J. Deren, Carlos Prieto, Luisa E. Bausá, Nicola A. Spaldin, Venkatraman Gopalan

研究成果: ジャーナルへの寄稿記事

1 引用 (Scopus)

抜粋

Polar instabilities are well known to be suppressed on scaling materials down to the nanoscale, when the electrostatic energy increase at surfaces exceeds lowering of the bulk polarization energy. Surprisingly, here we report an emergent low symmetry polar phase arising in nanoscale powders of CaTiO 3 , the original mineral named perovskite discovered in 1839 and considered nominally nonpolar at any finite temperature in the bulk. Using nonlinear optics and spectroscopy, X-ray diffraction, and microscopy studies, we discover a well-defined polar to non-polar transition at a T C = 350 K in these powders. The same polar phase is also seen as a surface layer in bulk CaTiO 3 single crystals, forming striking domains with in-plane polarization orientations. Density functional theory reveals that oxygen octahedral distortions in the surface layer lead to the stabilization of the observed monoclinic polar phase. These results reveal new ways of overcoming the scaling limits to polarization in perovskites.

元の言語英語
記事番号011103
ジャーナルAPL Materials
7
発行部数1
DOI
出版物ステータス出版済み - 1 1 2019

    フィンガープリント

All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Engineering(all)

これを引用

Ramirez, M. O., Lummen, T. T. A., Carrasco, I., Barnes, E., Aschauer, U., Stefanska, D., ... Gopalan, V. (2019). Emergent room temperature polar phase in CaTiO 3 nanoparticles and single crystals APL Materials, 7(1), [011103]. https://doi.org/10.1063/1.5078706