Thermal fluctuations of ferroelectric nanodomains in a ferroelectric-dielectric ${\mathrm{PbTiO}}_3/{\mathrm{SrTiO}}_3$ superlattice

Journal Article · 26 February 2017 · Physical Review Letters

DOI: https://doi.org/10.1103/PhysRevLett.118.097601 · OSTI ID:1345615

Zhang, Qingteng ^[1]; Dufresne, Eric M. ^[1]; Chen, Pice ^[1]; Park, Joonkyu ^[2]; Cosgriff, Margaret P. ^[2]; Yusuf, Mohammed ^[3]; Dong, Yongqi ^[4]; Fong, Dillon D. ^[1]; Zhou, Hua ^[1]; Cai, Zhonghou ^[1]; Harder, Ross J. ^[1]; Callori, Sara J. ^[5]; Dawber, Matthew ^[3]; Evans, Paul G. ^[2]; Sandy, Alec R. ^[1]

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1. Argonne National Lab. (ANL), Lemont, IL (United States)
2. Univ. of Wisconsin, Madison, WI (United States)
3. Stony Brook Univ., Stony Brook, NY (United States)
4. Argonne National Lab. (ANL), Lemont, IL (United States); Univ. of Science and Technology of China, Anhui (China)
5. Stony Brook Univ., Stony Brook, NY (United States); California State Univ. (CalState), San Bernardino, CA (United States)

Ferroelectric-dielectric superlattices consisting of alternating layers of ferroelectric PbTiO₃ and dielectric SrTiO₃ exhibit a disordered striped nanodomain pattern, with characteristic length scales of 6 nm for the domain periodicity and 30 nm for the in-plane coherence of the domain pattern. Spatial disorder in the domain pattern gives rise to coherent hard x-ray scattering patterns exhibiting intensity speckles. We show here using variable-temperature Bragg-geometry x-ray photon correlation spectroscopy that x-ray scattering patterns from the disordered domains exhibit a continuous temporal decorrelation due to spontaneous domain fluctuations. The temporal decorrelation can be described using a compressed exponential function, consistent with what has been observed in other systems with arrested dynamics. The fluctuation speeds up at higher temperatures and the thermal activation energy estimated from the Arrhenius model is 0.35±0.21 eV. As a result, the magnitude of the energy barrier implies that the complicated energy landscape of the domain structures is induced by pinning mechanisms and domain patterns fluctuate via the generation and annihilation of topological defects similar to soft materials such as block copolymers.

• Research Organization: Argonne National Lab. (ANL), Lemont, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Materials Sciences & Engineering Division; Stony Brook Univ., NY (United States); National Science Foundation (NSF)
• Grant/Contract Number: AC02-06CH11357; FG02-04ER46147
• OSTI ID: 1345615
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 9 Vol. 118; ISSN 0031-9007; ISSN PRLTAO
• Publisher: American Physical Society (APS)Copyright Statement
• Country of Publication: United States
• Language: English