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Abstract Exchange bias (EB), manifested as a hysteresis‐loop offset after field‐cooling, is demonstrated in perovskite‐structured ferromagnet/antiferromagnet (La0.67Sr0.33MnO3/YFeO3)nheterostructures grown on (100) SrTiO3substrates. Bilayer samples show an EB of 306 Oe at 50 K, whereas multilayers with five layers exhibit an exchange bias of up to 424 Oe at 50 K. A spin valve consisting of La0.67Sr0.33MnO3/SrTiO3/La0.67Sr0.33MnO3/YFeO3shows stable remanent configurations resulting from pinning of the upper La0.67Sr0.33MnO3layer by the YFeO3. In contrast, EB is not observed on (111)‐oriented SrTiO3substrates due to interface roughening. These results demonstrate YFeO3as an alternative orthoferrite antiferromagnet compared to BiFeO3and LaFeO3for incorporation into exchange‐biased heterostructures.
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Record high room temperature resistance switching in ferroelectric-gated Mott transistors unlocked by interfacial charge engineering
Abstract The superior size and power scaling potential of ferroelectric-gated Mott transistors makes them promising building blocks for developing energy-efficient memory and logic applications in the post-Moore’s Law era. The close to metallic carrier density in the Mott channel, however, imposes the bottleneck for achieving substantial field effect modulation via a solid-state gate. Previous studies have focused on optimizing the thickness, charge mobility, and carrier density of single-layer correlated channels, which have only led to moderate resistance switching at room temperature. Here, we report a record high nonvolatile resistance switching ratio of 38,440% at 300 K in a prototype Mott transistor consisting of a ferroelectric PbZr0.2Ti0.8O3gate and anRNiO3(R: rare earth)/La0.67Sr0.33MnO3composite channel. The ultrathin La0.67Sr0.33MnO3buffer layer not only tailors the carrier density profile inRNiO3through interfacial charge transfer, as corroborated by first-principles calculations, but also provides an extended screening layer that reduces the depolarization effect in the ferroelectric gate. Our study points to an effective material strategy for the functional design of complex oxide heterointerfaces that harnesses the competing roles of charge in field effect screening and ferroelectric depolarization effects.
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- Award ID(s):
- 1710461
- PAR ID:
- 10479229
- Publisher / Repository:
- Nature Publishing Group
- Date Published:
- Journal Name:
- Nature Communications
- Volume:
- 14
- Issue:
- 1
- ISSN:
- 2041-1723
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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