A5027641868- Ferroelectric and Piezoelectric Materials
- Advanced Memory and Neural Computing
- Multiferroics and related materials
- Magnetic and transport properties of perovskites and related materials
- Conducting polymers and applications
- Electronic and Structural Properties of Oxides
- Mechanical and Optical Resonators
- Advanced MEMS and NEMS Technologies
- Transition Metal Oxide Nanomaterials
- Ultrasonics and Acoustic Wave Propagation
- Advanced Condensed Matter Physics
- Surface Roughness and Optical Measurements
- Non-Destructive Testing Techniques
- Solid-state spectroscopy and crystallography
- Nonlocal and gradient elasticity in micro/nano structures
- Advanced Thermoelectric Materials and Devices
- Ferroelectric and Negative Capacitance Devices
- Dielectric properties of ceramics
- Nanowire Synthesis and Applications
Helmholtz-Zentrum Berlin für Materialien und Energie
2023-2024
University of Warwick
2017-2018
University of Nebraska–Lincoln
2012-2014
It is highly desirable to discover photovoltaic mechanisms that enable enhanced efficiency of solar cells. Here we report the bulk effect, which free from thermodynamic Shockley-Queisser limit but usually manifested only in noncentrosymmetric (piezoelectric or ferroelectric) materials, can be realized any semiconductor, including silicon, by mediation flexoelectric effect. We used either an atomic force microscope a micrometer-scale indentation system introduce strain gradients, thus...
In ferroelectric tunnel junctions, the polarization state of barrier influences quantum-mechanical tunneling through junction, resulting in electroresistance (TER). Here, we investigate Co/PbZr0.2Ti0.8O3/La0.7Sr0.3MnO3 junctions. The junctions with 1.2-1.6 nm (three to four unit cells) PbZr0.2Ti0.8O3 thickness and an area 0.04 μm2 can be switched by about 1 V yielding a resistive ON/OFF-ratio 300 at 0.4 V. Combined piezoresponse force microscopy electronic transport investigations these...
The bulk photovoltaic effect of ferroelectric semiconductors is increasingly being studied for potential applications in solar energy harvesting thanks to their unique charge separation mechanism and the resultant anomalous photovoltage. However, intrinsic properties regarding temperature dependence current its correlation with polarization such systems still require proper understanding. Here, by studying monodomain BiFeO3 thin films only a single variant, we demonstrate that possesses...
Abstract Synapses play a vital role in information processing, learning, and memory formation the brain. By emulating behavior of biological synapses, electronic synaptic devices hold promise enabling high‐performance, energy‐efficient, scalable neuromorphic computing. Ferroelectric memristive integrate characteristics both ferroelectric materials present far‐reaching potential as artificial synapses. Here, it is reported on new device silicon, field‐effect memristor, consisting an epitaxial...
Abstract The wide tunability of strongly correlated transition metal (TM) oxides stems from their complex electronic properties and the coupled degrees freedom. Among perovskite family, LaMO 3 (M = Ti-Ni) allows an M-dependent systematic study structure within same-structure-family motif. While most studies have been focusing on 3d TMs oxygen sites, role rare-earth site has far less explored. In this work, we use resonant inelastic X-ray scattering (RIXS) at lanthanum N 4,5 edges density...
Piezoresponse force microscopy imaging in conjunction with first-principles calculations provide strong evidence for room-temperature ferroelectricity epitaxially stabilized hexagonal TbMnO3 thin films, which the bulk form are orthorhombic structure. The obtained results demonstrate that new phases and functional properties of complex oxide materials can be strain-engineered using epitaxial growth.
Antiferroelectric tunnel junctions of La 0.7 Sr 0.3 MnO 3 /PbZrO /Co fabricated by pulsed laser deposition and sputtering are reported for the first time. The current–voltage curves highlight monostability type (threshold) resistive switching corresponding to antiferroelectric behavior PbZrO barrier down ≈4 nm thickness. Tunneling electroresistance values up 10 9 %, which is much higher than usual in ferroelectric junctions, observed at room temperature. attributed a combination nonpolar...
We report electrochemical metallization (ECM) resistive switching in polycrystalline YMnO 3 memristive devices using Al as an active electrode. Al/YMnO /Pt exhibit bipolar with a high R OFF / ON ratio of 10 4 , low operational voltages V Set ≈ 1.7 and Reset −0.36 good retention properties. The is intimately linked to the coexistence orthorhombic hexagonal phases. characterization these two nanocrystalline phases realized not only by X‐ray diffraction – which shown be unable reveal presence...
Phase Boundaries as Migration Paths In article number 2300494, Catherine Dubourdieu and co-workers report electrochemical metallization resistive switching in mixed hexagonal/orthorhombic polycrystalline YMnO3-based memristive devices using Al an active electrode. The migration of the Al3+ cations is localized oxygen-deficient grain boundaries between hexagonal orthorhombic nanocrystalline YMnO3 phases. Such paths prevent oxidation electrolyte remove randomness inherent to filament formation cells.