Metal–ferroelectric supercrystals with periodically curved metallic layers

• Published in: Nature materials 2021-04, Vol.20 (4), p.495-502
• Main Authors: Hadjimichael, Marios, Li, Yaqi, Zatterin, Edoardo, Chahine, Gilbert A., Conroy, Michele, Moore, Kalani, Connell, Eoghan N. O’, Ondrejkovic, Petr, Marton, Pavel, Hlinka, Jiri, Bangert, Ursel, Leake, Steven, Zubko, Pavlo
• Format: Article
• Language: English
• Subjects: 142/136; 639/301/119/544; 639/301/119/996; Biomaterials; Boundary conditions; Chemistry and Materials Science; Condensed Matter Physics; Correlation; Dimensional stability; Domains; Elastic deformation; Electric fields; Ferroelectric materials; Ferroelectricity; Heterostructures; Lead titanates; Materials Science; Microscopy; Nanotechnology; Optical and Electronic Materials; Scanning transmission electron microscopy; Structural hierarchy; Superlattices; Synchrotron radiation; Synchrotrons; X-ray diffraction
• ISSN: 1476-1122; 1476-4660
• DOI: 10.1038/s41563-020-00864-6

Simultaneous manipulation of multiple boundary conditions in nanoscale heterostructures offers a versatile route to stabilizing unusual structures and emergent phases. Here, we show that a stable supercrystal phase comprising a three-dimensional ordering of nanoscale domains with tailored periodicities can be engineered in PbTiO 3 –SrRuO 3 ferroelectric–metal superlattices. A combination of laboratory and synchrotron X-ray diffraction, piezoresponse force microscopy, scanning transmission electron microscopy and phase-field simulations reveals a complex hierarchical domain structure that forms to minimize the elastic and electrostatic energy. Large local deformations of the ferroelectric lattice are accommodated by periodic lattice modulations of the metallic SrRuO 3 layers with curvatures up to 10 7  m −1 . Our results show that multidomain ferroelectric systems can be exploited as versatile templates to induce large curvatures in correlated materials, and present a route for engineering correlated materials with modulated structural and electronic properties that can be controlled using electric fields. Ferroelectric superlattices can present a rich variety of phenomena. Here, in PbTiO 3 /SrRuO 3 superlattices, it is shown that a complex and stable hierarchical supercrystal can form, with the correlated metal of the SrRuO 3 layers showing large curvatures.