Designing antiphase boundaries by atomic control of heterointerfaces

Journal Article · 13 August 2018 · Proceedings of the National Academy of Sciences of the United States of America

DOI: https://doi.org/10.1073/pnas.1808812115 · OSTI ID:1464332

Wang, Zhen ^[1]; Guo, Hangwen ^[2]; Shao, Shuai ^[3]; Saghayezhian, Mohammad ^[2]; Li, Jun ^[4]; Fittipaldi, Rosalba ^[5]; Vecchione, Antonio ^[5]; Siwakoti, Prahald ^[2]; Zhu, Yimei ^[4]; Zhang, Jiandi ^[2]; Plummer, E. W. ^[2]

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1. Louisiana State Univ., Baton Rouge, LA (United States). Dept. of Physics & Astronomy; Brookhaven National Lab. (BNL), Upton, NY (United States). Condensed Matter Physics and Materials Science Dept.
2. Louisiana State Univ., Baton Rouge, LA (United States). Dept. of Physics & Astronomy
3. Louisiana State Univ., Baton Rouge, LA (United States). Dept. of Mechanical & Industrial Engineering
4. Brookhaven National Lab. (BNL), Upton, NY (United States). Condensed Matter Physics and Materials Science Dept.
5. Univ. di Salerno, Fisciano (Italy). Consiglio Nazionale Delle Ricerche-Superconducting and Other Innovative Materials and Devices Inst. (SPIN), Dipartimento di Fisica

Extended defects are known to have critical influences in achieving desired material performance. However, the nature of extended defect generation is highly elusive due to the presence of multiple nucleation mechanisms with close energetics. A strategy to design extended defects in a simple and clean way is thus highly desirable to advance the understanding of their role, improve material quality, and serve as a unique playground to discover new phenomena. In this work, we report an approach to create planar extended defects—antiphase boundaries (APB) —with well-defined origins via the combination of advanced growth, atomic-resolved electron microscopy, first-principals calculations, and defect theory. In La_2/3Sr_1/3MnO₃ thin film grown on Sr₂RuO₄ substrate, APBs in the film naturally nucleate at the step on the substrate/film interface. For a single step, the generated APBs tend to be nearly perpendicular to the interface and propragate toward the film surface. Interestingly, when two steps are close to each other, two corresponding APBs communicate and merge together, forming a unique triangle-shaped defect domain boundary. Such behavior has been ascribed, in general, to the minimization of the surface energy of the APB. Atomic-resolved electron microscopy shows that these APBs have an intriguing antipolar structure phase, thus having the potential as a general recipe to achieve ferroelectric-like domain walls for high-density nonvolatile memory.

• Research Organization: Brookhaven National Laboratory (BNL), Upton, NY (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• Grant/Contract Number: SC0012704; SC0002136; AC02-98CH10886
• OSTI ID: 1464332
• Alternate ID(s): OSTI ID: 1480961
• Report Number(s): BNL-209361-2018-JAAM
• Journal Information: Proceedings of the National Academy of Sciences of the United States of America, Vol. 115, Issue 38; ISSN 0027-8424
• Publisher: National Academy of Sciences, Washington, DC (United States)Copyright Statement
• Country of Publication: United States
• Language: English