A5006649962- Ferroelectric and Piezoelectric Materials
- Magnetic and transport properties of perovskites and related materials
- Multiferroics and related materials
- Advanced Condensed Matter Physics
- Dielectric materials and actuators
- Advanced Sensor and Energy Harvesting Materials
- Physics of Superconductivity and Magnetism
- Electronic and Structural Properties of Oxides
- High-pressure geophysics and materials
- Semiconductor materials and devices
- Crystallization and Solubility Studies
- Isotope Analysis in Ecology
- Shape Memory Alloy Transformations
- Magnetic Properties of Alloys
- Robotics and Automated Systems
- Astro and Planetary Science
- Intermetallics and Advanced Alloy Properties
- BIM and Construction Integration
- Infrastructure Maintenance and Monitoring
- Advanced Thermoelectric Materials and Devices
- Concrete Properties and Behavior
- Innovative Energy Harvesting Technologies
- Mass Spectrometry Techniques and Applications
- Ferroelectric and Negative Capacitance Devices
- Microwave Dielectric Ceramics Synthesis
Murata (Japan)
2016-2024
Osaka University
2001-2016
University of Cambridge
2016
Competitive cooling with capacitors Current large-scale devices use vapor compression refrigeration. The efficiency of air conditioners has been optimized, but they can be noisy and rely on problematic greenhouse gases. Two groups now present designs for electrocaloric using lead scandium tantalate that change temperature under an electric field. Y. Wang et al. obtained a very large heat flux only solid materials fan to remove from their device. Torello used fluids transfer, leading...
Competitive cooling with capacitors Current large-scale devices use vapor compression refrigeration. The efficiency of air conditioners has been optimized, but they can be noisy and rely on problematic greenhouse gases. Two groups now present designs for electrocaloric using lead scandium tantalate that change temperature under an electric field. Y. Wang et al. obtained a very large heat flux only solid materials fan to remove from their device. Torello used fluids transfer, leading...
Cooling through solid-state electrocaloric materials is an attractive replacement for vapor compression. Despite recent efforts, devices that are potentially commercially competitive have not been developed. We present cooler with a maximum temperature span of 20.9 kelvin and cooling power 4.2 watts under the moderate applied electric field 10 volts per micrometer without any observed breakdown. Moreover, coefficient performance, even taking into account energy expended on fluid pumping,...
Abstract Coming up with sustainable sources of electricity is one the grand challenges this century. The research field materials for energy harvesting stems from motivation, including thermoelectrics 1 , photovoltaics 2 and thermophotovoltaics 3 . Pyroelectric materials, converting temperature periodic variations in electricity, have been considered as sensors 4 harvesters 5–7 although we lack devices able to harvest joule range. Here develop a macroscopic thermal harvester made 42 g lead...
We show that scanning thermal microscopy can measure reversible electrocaloric (EC) effects in <40 μm-thick ceramic films of the relaxor ferroelectric 0.9Pb(Mg1/3Nb2/3)O3-0.1PbTiO3, with substrate present. recorded roughly same non-adiabatic temperature change (±0.23 K) for a thinner film was driven harder than thicker (±31 V μm−1 across 13 μm versus ±11 38 μm), because lay relatively closer to substantially larger adiabatic values we predicted by thermodynamic analysis electrical...
A multilayer capacitor comprising 19 layers of 38 μm-thick 0.9Pb(Mg1/3Nb2/3)O3–0.1PbTiO3 has elsewhere been shown to display electrocaloric temperature changes 2.2 K due field 24 V μm−1, near ∼100 °C. Here we demonstrate 1.2 in an equivalent device with 2.6 times the thermal mass, i.e., 49 that could tolerate 10.3 μm−1. Breakdown was compromised by increased number layers, and occurred at 10.5 μm−1 edge a near-surface inner electrode. Further optimization is required improve breakdown...
High resolution ultrasonic velocity measurements have been used to determine the temperature -- magnetic-field phase diagram of monoclinic multiferroic CuO. A new transition at TN3 = 230 K, corresponding an intermediate state between antiferromagnetic non-collinear spiral observed below TN2 229.3 K and paramagnetic phase, is revealed. Anomalies associated with a first order commensurate collinear are also TN1 213 K. For fields B along b axis, spin-flop detected 11 T - 13 lower temperatures....
Among ferroelectric crystals based on small molecules, plastic/ferroelectric are currently receiving particular attention because they can be used as bulk polycrystals. Herein, we show that an ionic molecular crystal, guanidinium tetrafluoroborate, exhibits significant malleability and multiaxial ferroelectricity despite the absence of a plastic crystal phase. Powder samples this processed into transparent crystalline plates either by press-forming or melt-growing. The high performance...
On increasing the active/total volume ratio of 0.9Pb(Mg1/3Nb2/3)O3–0.1PbTiO3 multilayer capacitors (MLCs), electrocaloric temperature change measured using a thermocouple near centre increases, until saturating to reveal nominally adiabatic limit (|ΔT| ~ 2.7 K for rapid field changes |ΔE| = 28.8 V µm−1). For all MLCs that we studied, practice multiplying by total/active heat capacity causes be overestimated small numerical factor. These findings highlight challenge associated with...
The high Curie temperature multiferroic compound CuO has a quasidegenerate magnetic ground state that makes it prone to manipulation by the so-called ``order-by-disorder'' mechanism. First principle computations supplemented with Monte Carlo simulations and experiments show isovalent doping allows us stabilize phase in nonferroelectric regions of pristine material diagram reaching 250% widening ferroelectric window 5% Zn doping. Our results allow validate importance on promoting...
Electrocaloric materials in the shape of multilayer capacitors are excellent working bodies to build cooling devices as they can exhibit large changes temperature triggered by voltage over range temperatures. However, high electric fields required drive such a effect and yet, their efficiency has been overlooked. Here we report on lead scandium tantalate capacitors. Hence, show that exchange 25 times more heat than electrical work generate this heat. Besides, observed these multilayers four...
Multilayer capacitors (MLCs) represent promising electrocaloric (EC) cooling elements because they operate at low voltages, possess large breakdown fields, contain inner electrodes that facilitate heat transfer, and exhibit a macroscopic volume of active EC material. However, almost ten years after were first suggested as elements, the internal flow has not been well studied. In this paper, we use an infrared camera to investigate within representative MLCs Pb(Mg,Nb)O3, achieve good...
Plastic crystals that show ferroelectricity are highly promising materials for a wide range of applications. Their inherent remarkable malleability and symmetric cubic structures in the plastic crystal phase ensure their related properties retained bulk polycrystals. To develop functional based on such plastic/ferroelectric crystals, methods to tune specific applications required. Here, we report preparation solid solutions ionic by mixing with common anion but different cations, or cation...
We report on the results of magnetic susceptibility and high field magnetization measurements single crystals SrCo2V2O8, which is regarded as an S = 1/2 quasi one-dimensional Ising-like antiferromagnet almost isostructural to BaCo2V2O8 that has exhibited a field-induced order-to-disorder transition. The have been performed at 1.4 K below Néel temperature TN 4.8 in pulsed fields up 50 T. dependence parallel c-axis (chain axis) broad maximum near 40 K, typical low dimensional antiferromagnet,...
HfO2 thin films with elemental substitutions were formed by chemical solution deposition. Bi substitution distorts the lattice and increases polarization value. (Bi,Nb) compensates charge balance to prevent formation of oxygen vacancies. The relative dielectric permittivity film 5 mol % La, Bi, Nb under an applied DC field was observed be up 78. constriction polarization–electric (P–E) curve disappears at a temperature lower than that where is maximum. phase transition from paraelectric...
By means of circularly polarized x rays at the Dy ${L}_{3}$ and Fe $K$ absorption edges, chiral structure electric quadrupole was investigated for a single crystal ${\mathrm{DyFe}}_{3}$(${\mathrm{BO}}_{3}$)${}_{4}$, in which both ions exhibit spiral arrangement. The integrated intensity resonant x-ray diffraction space-group forbidden reflections 004 005 is interpreted within dipole transitions from $2{p}_{\frac{3}{2}}$ to $5d$ $1s$ $4p$, respectively. We have confirmed that handedness...
Abstract Bulk PbMg 0.5 W O 3 (PMW) is an antiferroelectric in which electric field of 12 V μ m −1 sufficient to initiate a nominally reversible transition dipole-aligned (ferroelectric) phase if operating just below the Néel temperature T N , near room (Li et al 2021 Adv. Funct. Mater. 31 2101176). Here we describe multilayer capacitors (MLCs) PMW that permit 27 µ be applied without breakdown. Below driving partial (full) antiferroelectric–ferroelectric (AF–FE) over wide (narrow) range...
Improper ferroelectric Ca8−xSrx[Al12O24](MoO4)2 (x = 0–2) multilayer capacitors (MLCs) were fabricated to study their dielectric and properties for potential practical applications reversible switching of electric polarization by an field. The substitution Sr Ca caused a structural change from polar orthorhombic non-polar cubic phases at 297 K decreased the phase transition temperature (Tc). Spontaneous up ∼0.6 μC/cm2 was performed in Ca7.5Sr0.5[Al12O24](MoO4)2 Ca7Sr[Al12O24](MoO4)2 MLCs...
Since its inception six decades ago, astrobiology has diversified immensely to encompass several scientific questions including the origin and evolution of Terran life, organic chemical composition extraterrestrial objects, concept habitability, among others. The detection life beyond Earth forms main goal astrobiology, a significant one for space exploration in general. This galvanized connected with other critical areas investigation such as analysis meteorites early geological biological...
養生によるコンクリートの高耐久化技術の開発を目的として，新規に開発した特殊な型枠を用いることで，打込み直後のコンクリートの余剰水や気泡の排出と凝結後の速やかな給水による湿潤養生を，脱型せずに連続で行うことができる養生方法を開発した。壁高欄を模擬した大型部材の試験施工により標準的な施工方法を確立するとともに，耐久性試験を実施して表層の透気係数の低減，中性化の抑制，塩分浸透の抑制などの養生効果を確認した。加えて，橋梁の高欄壁に適用し，実構造物においてその効果を実証した。併せて，今後の養生方法の適用拡大へ向けた新たな給水方法の検討結果について報告する。