A5016978102- Multiferroics and related materials
- Ferroelectric and Piezoelectric Materials
- Magnetic and transport properties of perovskites and related materials
- Electronic and Structural Properties of Oxides
- Advanced Condensed Matter Physics
- Acoustic Wave Resonator Technologies
- ZnO doping and properties
- Transition Metal Oxide Nanomaterials
- Gas Sensing Nanomaterials and Sensors
- Magnetic properties of thin films
- Dielectric properties of ceramics
- Advanced Memory and Neural Computing
- Advanced Sensor and Energy Harvesting Materials
- Magnetic Properties and Synthesis of Ferrites
- Perovskite Materials and Applications
- Ga2O3 and related materials
- 2D Materials and Applications
- Physics of Superconductivity and Magnetism
- Ferroelectric and Negative Capacitance Devices
- Semiconductor materials and devices
- Magnetic Properties and Applications
- Force Microscopy Techniques and Applications
- Advanced Photocatalysis Techniques
- MXene and MAX Phase Materials
- Advancements in Battery Materials
National Tsing Hua University
2003-2025
National Yang Ming Chiao Tung University
2015-2024
Institute of Physics, Academia Sinica
2014-2024
National Applied Research Laboratories
2024
Taiwan Semiconductor Manufacturing Company (Taiwan)
2024
Max Planck Institute for Chemical Physics of Solids
2024
National Cheng Kung University
2018-2024
National Synchrotron Radiation Research Center
2012-2024
Kansai University
2024
State Key Laboratory of Food Science and Technology
2024
Piezoelectric materials, which convert mechanical to electrical energy and vice versa, are typically characterized by the intimate coexistence of two phases across a morphotropic phase boundary. Electrically switching one other yields large electromechanical coupling coefficients. Driven global environmental concerns, there is currently strong push discover practical lead-free piezoelectrics for device engineering. Using combination epitaxial growth techniques in conjunction with theoretical...
The authors report results of transport studies on high quality, fully epitaxial BiFeO3 thin films grown via pulsed laser deposition SrRuO3∕DyScO3 (110) substrates. Ferroelectric tests were conducted using symmetric and asymmetric device structures with either SrRuO3 or Pt top electrodes bottom electrodes. Comparison between these demonstrates the influence electrode selection dominant mechanism. Analysis film electrical response suggests Poole-Frenkel emission as limiting leakage current...
We report a photovoltaic effect in ferroelectric BiFeO3 thin films. The all-oxide heterostructures with SrRuO3 bottom and tin doped indium oxide top electrodes are characterized by open-circuit voltages ∼0.8–0.9 V external quantum efficiencies up to ∼10% when illuminated the appropriate light. Efficiencies at least an order of magnitude larger than maximum efficiency under sunlight (AM 1.5) thus far reported for ferroelectric-based devices. dependence measured voltage on film thickness...
The optical properties of epitaxial BiFeO3 thin films have been characterized in the visible range. Variable temperature spectra show an absorption onset near 2.17eV, a direct gap (2.667±0.005eV at 300K), and charge transfer excitations higher energy. Additionally, we report photoconductivity under illumination from 100mW∕cm2 white light source. A correlation is observed between magnitude postgrowth cooling pressure. Dark conductivities increased by order when comparing cooled 760 0.1Torr....
A reversal of magnetization requiring only the application an electric field can lead to low-power spintronic devices by eliminating conventional magnetic switching methods. Here we show a nonvolatile, room temperature determined in ferromagnet-multiferroic system. The effect is reversible and mediated interfacial coupling dictated multiferroic. Such electric-field control magnetoelectric device demonstrates avenue for next-generation, low-energy consumption spintronics.
Multiferroic materials, or materials that simultaneously possess two more ferroic order parameters, have returned to the forefront of research. Driven by desire achieve new functionalities—such as electrical control ferromagnetism at room temperature—researchers undertaken a concerted effort identify and understand complexities multiferroic materials. The ability create high quality thin film multiferroics stands one single most important landmarks in this flurry research activity. In review...
Detailed analysis of transport, magnetism, and x-ray absorption spectroscopy measurements on ultrathin ${\text{La}}_{0.7}{\text{Sr}}_{0.3}{\text{MnO}}_{3}$ films with thicknesses from 3 to 70 unit cells resulted in the identification a lower critical thickness for nonmetallic nonferromagnetic layer at interface ${\text{SrTiO}}_{3}$ (001) substrate only three $(\ensuremath{\sim}12\text{ }\text{\AA{}})$. Furthermore, linear-dichroism demonstrate presence preferred...
The transport physics of domain wall conductivity in La-doped bismuth ferrite (BiFeO3) has been probed using variable temperature conducting atomic force microscopy and piezoresponse samples with arrays walls the as-grown state. Nanoscale current measurements are investigated as a function bias shown to be consistent distinct electronic properties at leading changes observed local conductivity. Our observation is well described within band picture conduction. Finally, we demonstrate an...
We report the formation of a novel ferromagnetic state in antiferromagnet ${\mathrm{BiFeO}}_{3}$ at interface with ferromagnet ${\mathrm{La}}_{0.7}{\mathrm{Sr}}_{0.3}{\mathrm{MnO}}_{3}$. Using x-ray magnetic circular dichroism Mn and Fe ${L}_{2,3}$ edges, we discovered that development this spin structure is strongly associated onset significant exchange bias. Our results demonstrate directly related to an electronic orbital reconstruction interface, which supported by linearly polarized...
We report direct visualization of electrochemical lithiation and delithiation Au anodes in a commercial LiPF6/EC/DEC electrolyte for lithium ion batteries using transmission electron microscopy (TEM). The inhomogeneous lithiation, metal dendritic growth, decomposition, solid-electrolyte interface (SEI) formation are observed situ. These results shed lights on strategies improving electrode design reducing short-circuit failure the performance batteries.
Epitaxial oxide interfaces with broken translational symmetry have emerged as a central paradigm behind the novel behaviors of superlattices. Here, we use scanning transmission electron microscopy to demonstrate direct, quantitative unit-cell-by-unit-cell mapping lattice parameters and oxygen octahedral rotations across ${\mathrm{BiFeO}}_{3}\mathrm{\text{\ensuremath{-}}}{\mathrm{La}}_{0.7}{\mathrm{Sr}}_{0.3}{\mathrm{MnO}}_{3}$ interface elucidate how change crystal is accommodated. Combined...
3D heteroepitaxial growth of BiFeO3-CoFe2O4 nanostructures leads to unique morphological patterns depending on the substrate orientations. The morphologies nanostructures, estimated using Winterbottom construction (see figure), are dependent different nucleation modes that result from differences in surface energy anisotropy. dimensions increase as temperature increases and decrease rate increases.
We report direct experimental evidence for a room-temperature, $\ensuremath{\sim}130\text{ }\text{ }\ensuremath{\mu}\mathrm{C}/{\mathrm{cm}}^{2}$ ferroelectric polarization from the tetragonal-like ${\mathrm{BiFeO}}_{3}$ phase. The physical origin of this remarkable enhancement has been investigated by combination x-ray absorption spectroscopy, scanning transmission electron microscopy, and first principles calculations. A large strain-induced Fe-ion displacement relative to oxygen...
We demonstrate a direct correlation between the domain structure of multiferroic BiFeO3 thin films and exchange bias Co 0.9Fe 0.1/BiFeO3 heterostructures. Two distinct types interactions - an enhancement coercive field ( enhancement) combined with large shifts hysteresis loop bias) have been observed in these heterostructures, which depend directly on type crystallography nanoscale approximately 2 nm) walls film. show that magnitude interaction scales length 109 degrees ferroelectric BiFeO 3...
The control of material interfaces at the atomic level has led to novel interfacial properties and functionalities. In particular, study polar discontinuities between complex oxides lies frontier modern condensed matter research. Here we employ a combination experimental measurements theoretical calculations demonstrate bulk property, namely ferroelectric polarization, heteroepitaxial bilayer by precise atomic-scale interface engineering. More specifically, is achieved exploiting valence...