1. Strain‐Driven Mixed‐Phase Domain Architectures and Topological Transitions in Pb1−xSrxTiO3 Thin Films
- Author
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Kavle, Pravin, Zorn, Jacob A, Dasgupta, Arvind, Wang, Bo, Ramesh, Maya, Chen, Long‐Qing, and Martin, Lane W
- Subjects
Engineering ,Materials Engineering ,domains ,Euler characteristics ,ferroelectric thin films ,mixed-phase domain structures ,topology ,mixed-phase domain structures ,Physical Sciences ,Chemical Sciences ,Nanoscience & Nanotechnology ,Chemical sciences ,Physical sciences - Abstract
The potential for creating hierarchical domain structures, or mixtures of energetically degenerate phases with distinct patterns that can be modified continually, in ferroelectric thin films offers a pathway to control their mesoscale structure beyond lattice-mismatch strain with a substrate. Here, it is demonstrated that varying the strontium content provides deterministic strain-driven control of hierarchical domain structures in Pb1- x Srx TiO3 solid-solution thin films wherein two types, c/a and a1 /a2 , of nanodomains can coexist. Combining phase-field simulations, epitaxial thin-film growth, detailed structural, domain, and physical-property characterization, it is observed that the system undergoes a gradual transformation (with increasing strontium content) from droplet-like a1 /a2 domains in a c/a domain matrix, to a connected-labyrinth geometry of c/a domains, to a disconnected labyrinth structure of the same, and, finally, to droplet-like c/a domains in an a1 /a2 domain matrix. A relationship between the different mixed-phase modulation patterns and its topological nature is established. Annealing the connected-labyrinth structure leads to domain coarsening forming distinctive regions of parallel c/a and a1 /a2 domain stripes, offering additional design flexibility. Finally, it is found that the connected-labyrinth domain patterns exhibit the highest dielectric permittivity.
- Published
- 2022