The hafnate perovskites PbHfO3(antiferroelectric) and SrHfO3(“potential” ferroelectric) are studied as epitaxial thin films on SrTiO3(001) substrates with the added opportunity of observing a morphotropic phase boundary (MPB) in the Pb1−
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−
- NSF-PAR ID:
- 10371489
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Materials
- Volume:
- 34
- Issue:
- 37
- ISSN:
- 0935-9648
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Abstract x Srx HfO3system. The resulting (240)‐oriented PbHfO3(Pba 2) films exhibited antiferroelectric switching with a saturation polarization ≈53 µC cm−2at 1.6 MV cm−1, weak‐field dielectric constant ≈186 at 298 K, and an antiferroelectric‐to‐paraelectric phase transition at ≈518 K. (002)‐oriented SrHfO3films exhibited neither ferroelectric behavior nor evidence of a polarP 4mm phase . Instead, the SrHfO3films exhibited a weak‐field dielectric constant ≈25 at 298 K and no signs of a structural transition to a polar phase as a function of temperature (77–623 K) and electric field (–3 to 3 MV cm−1). While the lack of ferroelectric order in SrHfO3removes the potential for MPB, structural and property evolution of the Pb1−x Srx HfO3(0 ≤x < 1) system is explored. Strontium alloying increased the electric‐breakdown strength (E B) and decreased hysteresis loss, thus enhancing the capacitive energy storage density (U r) and efficiency (η). The composition, Pb0.5Sr0.5HfO3produced the best combination ofE B = 5.12 ± 0.5 MV cm−1,U r = 77 ± 5 J cm−3, and η = 97 ± 2%, well out‐performing PbHfO3and other antiferroelectric oxides. -
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