A5101909607- Multiferroics and related materials
- Magnetic and transport properties of perovskites and related materials
- Ferroelectric and Piezoelectric Materials
- Thermal Expansion and Ionic Conductivity
- Electronic and Structural Properties of Oxides
- Microwave Dielectric Ceramics Synthesis
- Magnetic properties of thin films
- Advanced Condensed Matter Physics
- Thermal properties of materials
- Thermodynamic and Structural Properties of Metals and Alloys
- Graphene research and applications
- Magnetic Properties of Alloys
- Semiconductor materials and devices
- Rare-earth and actinide compounds
- Advanced Electron Microscopy Techniques and Applications
- Particle Detector Development and Performance
- Magnesium Oxide Properties and Applications
- Advancements in Battery Materials
- Advanced X-ray Imaging Techniques
- Medical Imaging Techniques and Applications
- Advanced Thermoelectric Materials and Devices
- Dielectric properties of ceramics
- Magnetic Properties and Applications
- Transition Metal Oxide Nanomaterials
- Metallic Glasses and Amorphous Alloys
Peking University
2011-2024
China Institute of Atomic Energy
2008-2019
Virginia Commonwealth University
2011
NIST Center for Neutron Research
2011
University of Chinese Academy of Sciences
2008
Chinese Academy of Sciences
2006
Institute of High Energy Physics
1996
Magnetic hard nanocrystalline MnBi has been prepared by melt spinning and subsequent low temperature annealing. A coercivity of 2.5 T can be achieved at 540 K for with an average grain size about 20-30 nm. The iHc, mainly controlled the coherent magnetization rotation, shows a strong dependence on time grinding exhibits positive coefficient from 100 up to K. unique dependent behavior (magnetocrystalline anisotropy) relationship variations in crystal lattice ratio c/a temperatures. In...
Nontrivial topological structures offer a rich playground in condensed matters and promise alternative device configurations for post-Moore electronics. While recently number of polar topologies have been discovered confined ferroelectric PbTiO
Room-temperature polar skyrmions, which have been recently discovered in oxide superlattice, received considerable attention for their potential applications nanoelectronics owing to nanometer size, emergent chirality, and negative capacitance. For practical applications, manipulation using external stimuli is a prerequisite. Herein, we study the dynamics of individual skyrmions at nanoscale via situ scanning transmission electron microscopy. By monitoring electric-field-driven creation,...
Abstract Flexoelectricity is a type of ubiquitous and prominent electromechanical coupling, pertaining to the electrical polarization response mechanical strain gradients that not restricted by symmetry materials. However, large elastic deformation usually difficult achieve in most solids, gradient at minuscule challenging control. Here, we exploit exotic structural inhomogeneity grain boundary huge (~1.2 nm −1 ) within 3–4-unit cells, thus obtain atomic-scale flexoelectric up ~38 μC cm −2...
The orthorhombic rare-earth manganates and ferrites multiferroics are promising candidates for the next generation multistate spintronic devices. However, their ferroelectric polarization is small, transition temperature far below room (RT). improvement of ferroelectricity remains challenging. Here, through subtle strain defect engineering, an RT colossal 4.14 μC/cm 2 achieved in SmFeO 3−δ films, which two orders magnitude larger than its bulk also largest one among manganite ferrite family....
Abstract The infinite-layer nickelates, proposed as analogs to superconducting cuprates, provide a promising platform for exploring the mechanisms of unconventional superconductivity. However, superconductivity has been exclusively observed in thin films under atmospheric pressure, underscoring critical role heterointerface. Here, we employed advanced Scanning Transmission Electron Microscopy-Electron Energy Loss Spectroscopy technique thoroughly investigate atomic configuration,...
Nanoscale defects like grain boundaries (GBs) would introduce local phonon modes and affect the bulk materials' thermal, electrical, optical, mechanical properties. It is highly desirable to correlate atomic arrangements for individual precisely understand structure–property relation. Here we investigated localized of Al2O3 GBs by combination vibrational electron energy loss spectroscopy (EELS) in scanning transmission microscope density functional perturbation theory (DFPT). The differences...
Abstract Strongly correlated oxides with a broken symmetry could exhibit various phase transitions, such as superconductivity, magnetism and ferroelectricity. Construction of superlattices using these materials is effective to design crystal symmetries at atomic scale for emergent orderings phases. Here, antiferromagnetic Ruddlesden-Popper Sr 2 IrO 4 perovskite paraelectric (ferroelectric) SrTiO 3 (BaTiO ) are selected epitaxially fabricate engineering. An magnetoelectric transition achieved...
Remote heteroepitaxy is known to yield semiconductor films with better quality. However, the atomic mechanisms in systems large mismatches are still unclear. Herein, low-strain single-crystalline nitride achieved on highly mismatched (∼16.3%) sapphire via graphene-assisted remote heteroepitaxy. Because of a weaker interface potential, in-plane compressive strain at releases by 30%, and dislocations prevented. Meanwhile, lattice distortions epilayer disappear when structure climbs over steps...
Phonons are the primary heat carriers in non-metallic solids. In compositionally heterogeneous materials, thermal properties believed to be mainly governed by disrupted phonon transport due mass disorder and strain fluctuations, while effects of compositional fluctuation induced local states usually ignored. Here, scanning transmission electron microscopy energy loss spectroscopy sophisticated calculations, we identify vibrational ingredient-dependent interface modes Al x Ga 1 – N quantify...
Abstract Perovskite LaCoO 3 is a subject of extensive and ongoing investigation due to the delicate competition between high‐spin (HS) low‐spin (LS) states Co 3+ . On other hand, their indistinct free energy boundary poses significant challenge annihilate magnetically/electrically inert LS for yielding fully HS state. Here, electronic transformation from conventional isovalent mixed HS/LS state () into an unprecedented aliovalent demonstrated in monolayer confined by 5d SrIrO slabs via...
Polar domain walls in centrosymmetric ferroelastics induce inhomogeneity that is the origin of advantageous multifunctionality. In particular, polar promote charge-carrier separation and hence are promising for energy conversion applications overcome hurdles rate-limiting step traditional photoelectrochemical water splitting processes. Yet, while macroscopic studies investigate materials at device scale, this phenomenon general emergence during structural phase transition particular has...
Misfit dislocations at a heteroepitaxial interface produce huge strain and, thus, have significant impact on the properties of interface. Here, we use scanning transmission electron microscopy to demonstrate quantitative unit-cell-by-unit-cell mapping lattice parameters and octahedral rotations around misfit BiFeO 3 /SrRuO We find that field is achieved near dislocations, i.e., above 5% within first three unit cells core, which typically larger than from regular epitaxy thin-film approach,...
By use of density functional theory and nonequilibrium Green's function technique we have studied the electronic structure transport properties tubular Janus structures composed hybridized carbon (C) boron-nitride (BN) nanotubes (NTs) with caps at both ends. The effect chirality was probed by focusing on (5, 5) armchair (9, 0) zigzag structures, which similar radii are metallic in infinite length limit. study has revealed a number interesting properties: (1) highest-occupied molecular...
Defects exist ubiquitously in crystal materials, and usually exhibit a very different nature from the bulk matrix. Hence, their presence can have significant impacts on properties of devices. Although it is well accepted that defects are determined by unique atomic environments, precise knowledge such relationships far clear for most oxides because complexity difficulties characterization. Here, we fabricate 36.8° SrRuO3 grain boundary which transport measurements show spin-valve...
The strain modulation on the magnetic and electronic transport properties of ferromagnetic films is one hot topics due to practical applications in flexible wearable spintronic devices. However, large strain-induced saturation magnetization resistance change not easy achieve because most deposited substrates are polycrystalline or amorphous. Here, epitaxial γ'-Fe4N/mica fabricated by facing-target reactive sputtering. At a tensile with radius curvature (ROC) 3 mm, (Ms) film tailored...