Depth-Resolved X-Ray Photoelectron Spectroscopy Evidence of Intrinsic Polar States in HfO 2 -Based Ferroelectrics.

Autor: Hill MO; Department of Materials Science and Metallurgy, University of Cambridge, Cambridge, CB3 0FS, UK.; MAX IV Laboratory, Lund University, Lund, 221 00, Sweden., Kim JS; Department of Materials Science and Metallurgy, University of Cambridge, Cambridge, CB3 0FS, UK., Müller ML; Department of Materials Science and Metallurgy, University of Cambridge, Cambridge, CB3 0FS, UK., Phuyal D; Department of Materials Science and Metallurgy, University of Cambridge, Cambridge, CB3 0FS, UK.; Department of Applied Physics, KTH Royal Institute of Technology, Stockholm, 106 91, Sweden., Taper S; Department of Materials Science and Metallurgy, University of Cambridge, Cambridge, CB3 0FS, UK., Bansal M; Indian Institute of Science Education and Research Thiruvananthapuram, Thiruvananthapuram, Kerala, 695551, India., Becker MT; Department of Materials Science and Metallurgy, University of Cambridge, Cambridge, CB3 0FS, UK., Bakhit B; Department of Materials Science and Metallurgy, University of Cambridge, Cambridge, CB3 0FS, UK.; Department of Engineering, University of Cambridge, Cambridge, CB3 0FA, UK.; Department of Physics, Linköping University, Linköping, 581 83, Sweden., Maity T; Indian Institute of Science Education and Research Thiruvananthapuram, Thiruvananthapuram, Kerala, 695551, India., Monserrat B; Department of Materials Science and Metallurgy, University of Cambridge, Cambridge, CB3 0FS, UK., Martino GD; Department of Materials Science and Metallurgy, University of Cambridge, Cambridge, CB3 0FS, UK., Strkalj N; Department of Materials Science and Metallurgy, University of Cambridge, Cambridge, CB3 0FS, UK.; Center for Advanced Laser Techniques, Institute of Physics, Zagreb, 10000, Croatia., MacManus-Driscoll JL; Department of Materials Science and Metallurgy, University of Cambridge, Cambridge, CB3 0FS, UK.
Jazyk: angličtina
Zdroj: Advanced materials (Deerfield Beach, Fla.) [Adv Mater] 2024 Nov; Vol. 36 (45), pp. e2408572. Date of Electronic Publication: 2024 Sep 12.
DOI: 10.1002/adma.202408572
Abstrakt: The discovery of ferroelectricity in nanoscale hafnia-based oxide films has spurred interest in understanding their emergent properties. Investigation focuses on the size-dependent polarization behavior, which is sensitive to content and movement of oxygen vacancies. Though polarization switching and electrochemical reactions is shown to co-occur, their relationship remains unclear. This study employs X-ray photoelectron spectroscopy with depth sensitivity to examine changes in electrochemical states occurring during polarization switching. Contrasting Hf 0.5 Zr 0.5 O 2 (HZO) with Hf 0.88 La 0.04 Ta 0.08 O 2 (HLTO), a composition with an equivalent structure and comparable average ionic radius, electrochemical states are directly observed for specific polarization directions. Lower-polarization films exhibit more significant electrochemical changes upon switching, suggesting an indirect relationship between polarization and electrochemical state. This research illuminates the complex interplay between polarization and electrochemical dynamics, providing evidence for intrinsic polar states in HfO 2 -based ferroelectrics.
(© 2024 The Author(s). Advanced Materials published by Wiley‐VCH GmbH.)
Databáze: MEDLINE
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