Abstract
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.
| Original language | English |
|---|---|
| Article number | 011103 |
| Journal | APL Materials |
| Volume | 7 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - Jan 1 2019 |
| Externally published | Yes |
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All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Engineering(all)
Cite this
Emergent room temperature polar phase in CaTiO 3 nanoparticles and single crystals . / Ramirez, Mariola O.; Lummen, Tom T.A.; Carrasco, Irene; Barnes, Eftihia; Aschauer, Ulrich; Stefanska, Dagmara; Sen Gupta, Arnab; De Las Heras, Carmen; Akamatsu, Hirofumi; Holt, Martin; Molina, Pablo; Barnes, Andrew; Haislmaier, Ryan C.; Deren, Przemyslaw J.; Prieto, Carlos; Bausá, Luisa E.; Spaldin, Nicola A.; Gopalan, Venkatraman.
In: APL Materials, Vol. 7, No. 1, 011103, 01.01.2019.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Emergent room temperature polar phase in CaTiO 3 nanoparticles and single crystals
AU - Ramirez, Mariola O.
AU - Lummen, Tom T.A.
AU - Carrasco, Irene
AU - Barnes, Eftihia
AU - Aschauer, Ulrich
AU - Stefanska, Dagmara
AU - Sen Gupta, Arnab
AU - De Las Heras, Carmen
AU - Akamatsu, Hirofumi
AU - Holt, Martin
AU - Molina, Pablo
AU - Barnes, Andrew
AU - Haislmaier, Ryan C.
AU - Deren, Przemyslaw J.
AU - Prieto, Carlos
AU - Bausá, Luisa E.
AU - Spaldin, Nicola A.
AU - Gopalan, Venkatraman
PY - 2019/1/1
Y1 - 2019/1/1
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=85060483485&partnerID=8YFLogxK
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U2 - 10.1063/1.5078706
DO - 10.1063/1.5078706
M3 - Article
AN - SCOPUS:85060483485
VL - 7
JO - APL Materials
JF - APL Materials
SN - 2166-532X
IS - 1
M1 - 011103
ER -