Superior polarization retention through engineered domain wall pinning

Abstract

Ferroelectric materials possess a spontaneous polarization that is switchable by an electric field. Robust retention of switched polarization is critical for non-volatile nanoelectronic devices based on ferroelectrics, however, these materials often suffer from polarization relaxation, typically within days to a few weeks. Here we exploit designer-defect-engineered epitaxial BiFeO 3 films to demonstrate polarization retention with virtually no degradation in switched nanoscale domains for periods longer than 1 year. This represents a more than 2000% improvement over the best values hitherto reported. Scanning probe microscopybased dynamic switching measurements reveal a significantly increased activation field for domain wall movement. Atomic resolution scanning transmission electron microscopy indicates that nanoscale defect pockets pervade the entire film thickness. These defects act as highly efficient domain wall pinning centres, resulting in anomalous retention. Our findings demonstrate that defects can be exploited in a positive manner to solve reliability issues in ferroelectric films used in functional devices.

Emerging Opportunities for 2D Semiconductor/Ferroelectric Transistor‐Structure Devices

“…Compared to P(VDF-TrFE), oxide ferroelectrics like PZT and BTO generally show fast switching speed (sub-ns scale), low switching electric field (≈100 kV cm −1 ) and high remnant polarization (≈100 µC cm −2 ), all desired for high-performance memory operation. [23,38,167] Moreover, leveraging on the "on demand" tuning of structural and electronic properties of these complex oxides, ultralong retention (approximately years) and diminished polarization fatigue enabled superior endurance (>10 14 cycles) can be realized in oxide ferroelectrics, [168][169][170] implying their great potential for nonvolatile memories. [171] A typical oxide ferroelectric based 2D FeFET is shown in Figure 6d, where the PZT films grown on SrTiO 3 single crystal substrates were used as the bottom gate dielectric and p-type WSe 2 was the transport channel.…”

The Experimentalist's Guide to the Cycloid, or Noncollinear Antiferromagnetism in Epitaxial BiFeO3

“…An alternative avenue for novel device opportunities is the integration of the unique magnetic properties of BFO with its other virtues, such as its nonlinear optical properties, [ 62,289 ] conductive domain walls useful for memories, [ 90,290,291 ] as well as its bulk photovoltaic effect, useful for energy harvesting. [ 62,292 ]…”

Additive Manufacturing of Piezoelectric Materials

“…[149][150][151] This is due to the adjustment of the binding state at the interface, such as lattice matching, interface components, stress and strain, to improve residual polarization, promote polarization rotation, and enhance the spontaneous polarization ability and domain wall motion speed. [152][153][154] In addition, the oriented Figure 18. Prospects for future development to piezoelectric materials prepared by additive manufacturing.…”

“…[ 149–151 ] This is due to the adjustment of the binding state at the interface, such as lattice matching, interface components, stress and strain, to improve residual polarization, promote polarization rotation, and enhance the spontaneous polarization ability and domain wall motion speed. [ 152–154 ] In addition, the oriented polycrystal not only suggests the excellent piezoelectric performance of a single crystal, but also reflects the performance superposition multiplier effect brought about by the uniform orientation of the polycrystalline structure. [ 155,156 ] The construction of high‐density heteroepitaxial interface‐oriented piezoelectric nanocomplex provides a path for the development of new high‐performance lead‐free piezoelectric materials and has great potential for the fabrication of high‐performance piezoelectric devices. Improvement of packaging technology: The packaging of piezoelectric components plays a role in the mechanical and environmental protection of the circuit, so that it can improve the stability, safety, and service life of electronic components.…”