Epitaxial Strain Enhanced Ferroelectric Polarization toward a Giant Tunneling Electroresistance.
ACS Nano
; 18(11): 7989-8001, 2024 Mar 19.
Article
em En
| MEDLINE
| ID: mdl-38438318
ABSTRACT
A substantial ferroelectric polarization is the key for designing high-performance ferroelectric nonvolatile memories. As a promising candidate system, the BaTiO3/La0.67Sr0.33MnO3 (BTO/LSMO) ferroelectric/ferromagnetic heterostructure has attracted a lot of attention thanks to the merits of high Curie temperature, large spin polarization, and low ferroelectric coercivity. Nevertheless, the BTO/LSMO heterostructure suffers from a moderate FE polarization, primarily due to the quick film-thickness-driven strain relaxation. In response to this challenge, we propose an approach for enhancing the FE properties of BTO films by using a Sr3Al2O6 (SAO) buffering layer to mitigate the interfacial strain relaxation. The continuously tunable strain allows us to illustrate the linear dependence of polarization on epitaxial strain with a large strain-sensitive coefficient of â¼27 µC/cm2 per percent strain. This results in a giant polarization of â¼80 µC/cm2 on the BTO/LSMO interface. Leveraging this large polarization, we achieved a giant tunneling electroresistance (TER) of â¼105 in SAO-buffered Pt/BTO/LSMO ferroelectric tunnel junctions (FTJs). Our research uncovers the fundamental interplay between strain, polarization magnitude, and device performance, such as on/off ratio, thereby advancing the potential of FTJs for next-generation information storage applications.
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01-internacional
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MEDLINE
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En
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ACS Nano
Ano de publicação:
2024
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Article