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Tuning Negative Capacitance state inPbZr<sub>0.2</sub>Ti<sub>0.8</sub>O<sub>3</sub>/SrTiO<sub>3</sub>Heterostructures via Layer Thickness Ratio

ORAL

Abstract

The negative capacitance (NC) effect in a ferroelectric (FE) can be stabilized by interfacing with a dielectric (DE) layer for developing steep slope transistors. In this study, we examine the transition from FE to DE ground state in PbZr0.2Ti0.8O3/SrTiO3 (PZT/STO) heterostructures using the transient NC measurements. We deposit epitaxial PZT/STO bilayers with a total thickness of 100 nm on 10 nm LaNiO3 buffered (001) STO substrates. With decreasing FE-DE thickness ratio (r), the remanent polarization of the stack decreases monotonically and exhibits an abrupt drop at the critical ratio of rc = 8-7, which is consistent with the Landau theory modeling of the free energy profile. Upon polarization switching, we observe the charge damping associated with the transient NC mode within 2 μs. Modeling the charge switching dynamics in the r = 8 sample reveals a domain wall motion limited behavior, which evolves to a multidomain state in the r = 7 sample. The transient NC mode is quenched in the r = 6 sample, consistent with the suppressed ferroelectric order. Our study provides critical material information for designing complex oxide-based NC field-effect transistors for low-power nanoelectronics.   

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Publication: Y. Hao et al., Phys. Rev. Appl. 16, 034004 (2021).

Presenters

  • Yifei Hao

    Department of Physics and Astronomy & Nebraska Center for Materials and Nanoscience, University of Nebraska-Lincoln, Department of Physics and Astronomy & Nebraska Center for Materials and Nanoscience, University of Nebraska - Lincoln

Authors

  • Yifei Hao

    Department of Physics and Astronomy & Nebraska Center for Materials and Nanoscience, University of Nebraska-Lincoln, Department of Physics and Astronomy & Nebraska Center for Materials and Nanoscience, University of Nebraska - Lincoln

  • Tianlin Li

    Department of Physics and Astronomy & Nebraska Center for Materials and Nanoscience, University of Nebraska - Lincoln

  • Yu Yun

    Department of Physics and Astronomy & Nebraska Center for Materials and Nanoscience, University of Nebraska - Lincoln, University of Nebraska - Lincoln

  • Xin Li

    Department of Physics and Astronomy & Nebraska Center for Materials and Nanoscience, University of Nebraska - Lincoln, University of Nebraska - Lincoln

  • Xuegang Chen

    University of Nebraska - LincolnDepartment of Physics and Astronomy & Nebraska Center for Materials and Nanoscience, University of Nebraska - Lincoln

  • Jingfeng Song

    Department of Physics and Astronomy & Nebraska Center for Materials and Nanoscience, University of Nebraska - Lincoln

  • Zahra Ahmadi

    Department of Mechanical and Materials Engineering & Nebraska Center for Materials and Nanoscience, University of Nebraska - Lincoln, Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln

  • Jeffrey Shield

    University of Nebraska-Lincoln, Department of Mechanical and Materials Engineering & Nebraska Center for Materials and Nanoscience, University of Nebraska - Lincoln, Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln

  • Xiaoshan Xu

    University of Nebraska - Lincoln, Department of Physics and Astronomy & Nebraska Center for Materials and Nanoscience, University of Nebraska - Lincoln

  • Xia Hong

    Department of Physics and Astronomy & Nebraska Center for Materials and Nanoscience, University of Nebraska-Lincoln, Department of Physics and Astronomy & Nebraska Center for Materials and Nanoscience, University of Nebraska - Lincoln, University of Nebraska-Lincoln, University of Nebraska, Lincoln