A5045896881- Magnetic properties of thin films
- Magnetic and transport properties of perovskites and related materials
- Rare-earth and actinide compounds
- ZnO doping and properties
- Iron-based superconductors research
- Advanced Condensed Matter Physics
- Physics of Superconductivity and Magnetism
- Topological Materials and Phenomena
- Multiferroics and related materials
- Magnetic Properties and Applications
- Magnetic Properties of Alloys
- Heusler alloys: electronic and magnetic properties
- Theoretical and Computational Physics
- Quantum and electron transport phenomena
- Electronic and Structural Properties of Oxides
- Graphene research and applications
- Superconductivity in MgB2 and Alloys
- Metallic Glasses and Amorphous Alloys
- Magnetic Properties and Synthesis of Ferrites
- Ferroelectric and Piezoelectric Materials
- Copper-based nanomaterials and applications
- Advanced Thermoelectric Materials and Devices
- 2D Materials and Applications
- Inorganic Chemistry and Materials
- Chalcogenide Semiconductor Thin Films
Sogang University
2016-2025
Osaka University
2024
Korea Maritime Institute
2023
Conference Board
2013-2019
Alpha Omega Electromagnetics (United States)
2018-2019
Government of the Republic of Korea
2017
Mississippi State University
2016
Texas Tech University
2016
Korea Institute of Materials Science
2016
University of Alabama
2016
Hollow nan': face-centered cubic (fcc) Co nanoparallelepipeds were prepared by thermolysis of solid fcc CoO in oleylamine (see TEM image). The are reduced the surfactant to form hollow nanoparallelepipeds. Voids and generated on surface removal oxide as carbon monoxide. Detailed facts importance specialist readers published "Supporting Information". Such documents peer-reviewed, but not copy-edited or typeset. They made available submitted authors. Please note: publisher is responsible for...
We have studied the surface termination of atomically flat SrTiO3 surfaces treated by chemical etching and subsequent thermal annealing, for all commercially available orientations (001), (110), (111). Atomic force microscopy confirms that our treatment processes produce unit cell steps with terrace structures. also determined topmost atomic layer through time-of-flight mass spectroscopy. found three exhibit a Ti-rich surface. Our observation opens doors interface engineering along [110]...
We have observed unusual ferromagnetic properties in single-crystalline CoSi nanowire ensemble, marked contrast to the diamagnetic bulk. High-density freestanding nanowires with B20 crystal structure are synthesized by a vapor-transport-based method. The reaction of cobalt chloride precursor Si substrate produces high-aspect-ratio nanowires. high-resolution transmission electron microscopy and diffraction studies reveal superlattice twice lattice parameter simple cubic lattice....
As cobalt is an important ferromagnetic material and the nanofibrous shape greatly improves magnetic properties, we are introducing nanofibers encapsulated in graphite shell to gain advantages of as well produce protected materials. An electrospun nanofiber mat consisting acetate poly(vinyl alcohol) has been calcined argon atmosphere at 850 °C. Calcination inert leads production pure which strongly enhanced graphitization utilized polymer form a shell. Physicochemical characterization...
The thermoelectric properties of Mg–Sb single crystals, which are compared with their polycrystalline counterparts, enhanced by introducing Mn.
Spin-orbit torques, including the Rashba and spin Hall effects, have been widely observed investigated in various systems. Since interesting spin-orbit torque (SOT) arises at interface between heavy nonmagnetic metals ferromagnetic metals, most studies focused on ultra-thin layer with perpendicular magnetic anisotropy. Here, we measured effective longitudinal transverse fields of bulk anisotropy Pd/FePd (1.54 to 2.43 nm)/MgO systems using harmonic methods careful correction procedures. We...
We have investigated experimentally the effects of n-type impurities such as Al and H on magnetic properties ZnCoO. The carrier density changes slightly upon introduction hydrogen but increases significantly in case Al. A measurement circular dichroism indicates that, two impurities, only induces ferromagnetism Our experimental data suggest unlike Al, plays an important role enhancement ferromagnetic spin-spin interactions that goes much beyond a carrier-mediated effect.
Multiferroic hexagonal TbMnO3 thin films have been epitaxially stabilized on substrates with in-plane symmetry by pulsed laser deposition. The show ferroelectricity below ca. 60 K a remnant polarization 20 times larger compared to its orthorhombic bulk phase. In addition, these samples an electric-field-induced antiferroelectric-to-ferroelectric phase transition.
We report a new class of three-dimensional topological insulators transition metal doped Bi2Se3, TrxBi2Se3, and Bi2-xTrxSe3 (Tr = Cr, Fe, Cu) with x 0.15, for the intercalation substitution cases. With varying doping atoms, great variety properties are observed in single crystal form. The Cu-intercalated shows superconducting behavior below 3 K, where diamagnetic signal is found. increase carrier density at low temperature likely to be responsible superconductivity. magnetically case...
Experimental results for the susceptibility, magnetization, specific heat, 4f occupation number, Hall effect, and magnetoresistance single crystals of intermediate valence (IV) compound YbAl3 show that, in addition to Kondo temperature scale T(K) approximately 670 K, there is a low T(coh) 30-40 K onset Fermi liquid coherence. Furthermore, crossover from regime high local moment slower than predicted by Anderson impurity model. We suggest that these effects are generic IV compounds we discuss...
(Mn, Zn) co-doped CdS (Cd0.8Mn0.01Zn0.17S, Cd0.78Mn0.15Zn0.07S, and Cd0.67Mn0.3Zn0.07S) nanowires (or nanobelts) were synthesized using the vapor transport method. Their X-ray diffraction patterns reveal a significant contraction of lattice constants up to 1.5%, due incorporation Mn Zn. The electronic structures Cd, Mn, Zn atoms probed by photoelectron spectroscopy compared with those Mn-doped (Cd1-xMnxS, where x = 0.1, 0.2, 0.3) nanowires. As concentration increases, binding energy Cd 3d,...
Vertically aligned Fe2O3 nanowire arrays were synthesized by the thermal oxidation of Fe foil. They consist single-crystalline rhombohedral α-Fe2O3 nanocrystals grown along [112¯0] direction. Most nanowires have a sharp tip (diameter=50nm) and beltlike base. The magnetization measurement reveals Morin temperature 125K unique magnetic anisotropy due to easy axis magnetocrystalline perpendicular axis.
We fabricated epitaxial thin films of hexagonal DyMnO3, which otherwise form in a bulk perovskite structure, via deposition on Pt(111)//Al2O3 (0001) and YSZ(111) substrates: each has in-plane symmetry. The polarization hysteresis loop demonstrated the existence ferroelectricity our DyMnO3 at least below 70 K. observed 2.2 uC/cm^2 remnant 25 K corresponded to enhancement by factor 10 compared that orthorhombic DyMnO3. Interestingly, this system showed an antiferroelectric-like feature its...
Bi2Te3 is a well-known thermoelectric material for room-temperature operations because it has high Seebeck coefficient, and the charge carrier type easily tunable. However, of Bi2Se3 not tunable, which one weaknesses applications, in spite its coefficient. Here, we report tuning carriers from n to p by doping Mn into Bi sites. The up level 5% changes above doping. temperature-dependent resistivity Bi2−xMnxSe3 shows metallic behavior x < 0.05, while ≥ an upturn at low temperatures....
We report an intriguing magnetodielectric coupling in BaTiO3∕γ-Fe2O3 dielectric core/ferrimagnetic shell nanoparticles. The constant steeply increases with magnetic field, and the frequency dependent curve shows a resonancelike peak at high temperatures, while it decreases smoothly field no appears low temperatures. attribute observed to Maxwell-Wagner effect combined magnetoresistance temperatures possible spin-lattice its modification near interfaces
We report the simultaneous and selective synthesis of single-crystalline Co(n)Si NWs (n = 1-3) their corresponding crystal structures--simple cubic (CoSi), orthorhombic (Co(2)Si), face-centered (Co(3)Si)--following a composition change. were synthesized by placing sapphire substrates along temperature gradient. The synthetic process is successful demonstration tuning chemical in NWs. detailed structure Co(2)Si Co(3)Si are reported for first time including bulk nanostructure phases....
Among the common ferromagnetic metals, cobalt has distinct magnetic properties, so incorporation of nanoparticles in nickel nanofibers, which reveals better properties compared with bulk, might have considerable impact. In this study, we are introducing cobalt-doped nanofibers prepared by electrospinning. Electrospinning a colloidal solution rather than sol−gel (which is widely utilized conventional electrospinning technique) been invoked as novel strategy to prepare nanoparticles/nickel...
Fe-doped BaTiO3 thin films were grown on (001) oriented SrTiO3 substrates using pulsed-laser deposition technique. These had a single-phase character and good epitaxial relationship with the substrate. Polarization-electric field (P-E) hysteresis revealed saturated polarization remnant (Pr) of 13.5 μC/cm2 for 10 mol. % films. Further increase composition resulted in large leakage currents reduction polarization. The piezoelectric domain switching was confirmed by local force microscopy...
Abstract There are many interests to achieve long-range magnetic order in topological insulators of Bi 2 Se 3 or Te by doping transition metals such as Fe and Mn. The act not only dopants but also electric because they usually divalent. However, if the elements rare-earth Gd, which trivalent, moments can be introduced. We fabricated single crystals 2-x Gd x (0 ≤ × 0.2), we observed phase change from paramagnetic (PM) antiferromagnetic (AFM) increasing x. This PM-to-AFM agrees with density...