Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Magnetic Properties of Cluster Glassy Ni/NiO Core-Shell Nanoparticles: an Investigation of Their Static and Dynamic Magnetization.

ABSTRACT: We review the phenomenology of the exchange bias and its related effects in core-shell nanocrystals. The static and dynamic properties of the magnetization for ferromagnetic Ni-core and antiferromagnetic NiO-shell cluster glassy nanoparticles are examined, along with the pinning-depinning process, through the measurement of the conventional exchange bias, and associated with different cooling fields and particle sizes. Two significant indexes for the dipolar interaction n and multi-anisotropic barrier ? derived from the dynamic magnetization are proposed, which provide a unified picture of the exchange bias mechanism and insight into the influence of the cooling field.

SUBMITTER: Ji JY

PROVIDER: S-EPMC4452478 | biostudies-other | 2015 Dec

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Publications

Magnetic Properties of Cluster Glassy Ni/NiO Core-Shell Nanoparticles: an Investigation of Their Static and Dynamic Magnetization.

Ji Jhong-Yi JY Shih Po-Hsun PH Chan Ting-Shan TS Ma Yuan-Ron YR Wu Sheng Yun SY

Nanoscale research letters 20150528 1

We review the phenomenology of the exchange bias and its related effects in core-shell nanocrystals. The static and dynamic properties of the magnetization for ferromagnetic Ni-core and antiferromagnetic NiO-shell cluster glassy nanoparticles are examined, along with the pinning-depinning process, through the measurement of the conventional exchange bias, and associated with different cooling fields and particle sizes. Two significant indexes for the dipolar interaction n and multi-anisotropic b ...[more]

PMID: 26055474

Similar Datasets

High Density Arrayed Ni/NiO Core-shell Nanospheres Evenly Distributed on Graphene for Ultrahigh Performance Supercapacitor.

Project description:A novel NiO/Ni/RGO three-dimensional core-shell architecture consisting of Ni nanoparticles as core, NiO as shell and reduced graphene oxide (RGO) as conductivity layer, has been constructed by redox reactions with hydrothermal method and heat treatment. High density arrayed nickel nanoparticles (20?nm diameter) semi-coated by a 3?nm thick layer of NiO are evenly distributed on the surface of graphene. This elaborate design not only uses abundant NiO surfaces to provide a wealth of active sites, but also bridges electrochemical active NiO shell and graphene by Ni core to construct an interconnected 3D conductive network. Since both electrochemical activity and excellent conductivity are reserved in this Ni/NiO core-shell/graphene layer 3D structure, the as-prepared electrode material exhibits an extremely high specific capacitance (2048.3?F?g-1 at current density of 1?A?g-1) and excellent cycle stability (77.8% capacitance retention after 10000 cycles at current density of 50?A?g-1). The novel method presented here is easy and effective and would provide reference for the preparation of other high performance supercapacitor electrodes.

| S-EPMC5735128 | biostudies-literature

Room Temperature Magnetic Memory Effect in Cluster-Glassy Fe-doped NiO Nanoparticles.

Project description:The Fe-doped NiO nanoparticles that were synthesized using a co-precipitation method are characterized by enhanced room-temperature ferromagnetic property evident from magnetic measurements. Neutron powder diffraction experiments suggested an increment of the magnetic moment of 3d ions in the nanoparticles as a function of Fe-concentration. The temperature, time, and field-dependent magnetization measurements show that the effect of Fe-doping in NiO has enhanced the intraparticle interactions due to formed defect clusters. The intraparticle interactions are proposed to bring additional magnetic anisotropy energy barriers that affect the overall magnetic moment relaxation process and emerging as room temperature magnetic memory. The outcome of this study is attractive for the future development of the room temperature ferromagnetic oxide system to facilitate the integration of spintronic devices and understanding of their fundamental physics.

| S-EPMC7407623 | biostudies-literature

Design of NiO Flakes@CoMoO<sub>4</sub> Nanosheets Core-Shell Architecture on Ni Foam for High-Performance Supercapacitors.

Project description:As typical electrode materials for supercapacitors, low specific capacitance and insufficient cycling stability of transition metal oxides (TMOs) are still the problems that need to be solved. Design of core-shell structure is considered as an effective method for preparation of high-performance electrode materials. In this work, NiO flakes@CoMoO4 nanosheets/Ni foam (NiO flakes@CoMoO4 NSs/NF) core-shell architecture was constructed by a two-step hydrothermal method. Interestingly, the CoMoO4 NSs are vertically grown on the surface of NiO flakes, forming a two-dimensional (2D) branched core-shell structure. The porous core-shell architecture has relatively high surface area, effective ions channels, and abundant redox sites, resulting in excellent electrochemical performance. As a positive electrode for supercapacitors, NiO flakes@CoMoO4 NSs/NF core-shell architecture exhibits excellent capacitive performance in terms of high specific capacitance (1097 F/g at 1 A/g) and outstanding cycling stability (97.5% after 2000 circles). The assembled asymmetric supercapacitor (ASC) of NiO flakes@CoMoO4 NSs/NF//active carbon (AC)/NF possesses a maximum energy density of 25.8 Wh/kg at power density of 894.7 W/kg. The results demonstrate that NiO flakes@CoMoO4 NSs/NF electrode displays potential applications in supercapacitors and the design of 2D branched core-shell architecture paves an ideal way to obtain high-performance TMOs electrodes.

| S-EPMC6606686 | biostudies-literature

Static and Dynamic Magnetization of Gradient FeNi Alloy Nanowire.

Project description:FeNi binary nanowires with gradient composition are fabricated by the electrodeposition method. The energy dispersive spec-trometer line-sweep results show that the composition changes gradually along the wire axis. The gradient FeNi nanowires exhibit polycrystalline and crystal twinning at different areas along the nanowire axis, with a textured face-centered cubic structure. The static and dynamic magnetization properties are characterized by a hysteresis loop and ferromagnetic reso-nance with pumping frequencies from 12- 40 GHz. The linear dispersion of the pumping frequency vs: the resonance field has been observed with the applied bias field higher than the saturation field, corresponding to the hysteresis loop. The field-sweep linewidths decrease with increasing pumping frequency, and the frequency-sweep linewidths stay nearly constant at the unsaturated region. The linewidth is a Gilbert type at the saturated state, with damping of 0.035 ± 0.003. Compared with the damping of the homogeneous composition FeNi nanowire (a = 0.044 ± 0.005), the gradient FeNi nanowire may have less eddy current damping, which could make it an alternative candidate for spintronics and microstrip antennas.

| S-EPMC4750065 | biostudies-other

Core Shell Investigation of 2-nitroimidazole.

Project description:Tunability and selectivity of synchrotron radiation have been used to study the excitation and ionization of 2-nitroimidazole at the C, N, and O K-edges. The combination of a set of different measurements (X-ray photoelectron spectroscopy, near-edge photoabsorption spectroscopy, Resonant Auger electron spectroscopy, and mass spectrometry) and computational modeling have successfully disclosed local effects due to the chemical environment on both excitation/ionization and fragmentation of the molecule.

| S-EPMC6454003 | biostudies-literature

Bifunctional hexagonal Ni/NiO nanostructures: influence of the core-shell phase on magnetism, electrochemical sensing of serotonin, and catalytic reduction of 4-nitrophenol.

Project description:Ni0/NiO (nickel/nickel oxide) core-shell nanostructures were synthesized through a facile combustible redox reaction. Remarkably, the hetero-phase boundary with different crystalline orientations offered dual properties, which helped in bifunctional catalysis. Presence of a metallic Ni phase changed physicochemical properties and some emerging applications (magnetic properties, optical conductivity, electrochemical sensitivity, catalytic behaviour) could be foreseen. Moreover, formation of a NiO layer on metal surface prevented magnetism-induced aggregation, arrested further oxidation by hindering oxygen diffusion, and acted as a good sorbent to enhance the surface adsorption of the analyte. Hexagonal Ni/NiO nanostructures manifested well-defined ferromagnetic behavior and the catalyst could be collected easily at the end of the catalytic reduction. Ni/NiO core-shell catalysts at the nanoscale had outstanding catalytic performance (reduction of 4-nitrophenol to 4-aminophenol) compared with pure NiO catalysts beyond a reaction time of ∼9 min. The estimated sensitivity, limit of detection and limit of quantification towards the electrochemical sensing of serotonin were 0.185, 0.43 and 1.47 μM μA-1, respectively. These results suggest that a bifunctional Ni/NiO nanostructure could be a suitable catalyst for electrochemical detection of serotonin and reduction of 4-nitrophenol.

| S-EPMC9417847 | biostudies-literature

Fabrication of Hierarchical ZnO@NiO Core-Shell Heterostructures for Improved Photocatalytic Performance.

Project description:ZnO@NiO core-shell heterostructures with high photocatalytic efficiency and reusability were prepared via electrochemical deposition on carbon fiber cloth substrates. Their photocatalytic properties were investigated by measuring the degradation of rhodamine B and methyl orange (MO) under ultraviolet light irradiation. The photodegradation efficiency of the ZnO@NiO heterostructures toward both dyes was better than those of the pure ZnO nanorods and NiO nanosheets. The higher performance could be attributed to the formation of p-n heterojunction between ZnO and NiO. Especially, the ZnO@NiO heterostructure formed upon deposition of NiO for 10 min degraded 95% of MO under ultraviolet light irradiation for 180 min. The high photodegradation efficiency of the ZnO@NiO heterostructures was also attributed to the high separation efficiency of photogenerated carriers, as confirmed by the higher photocurrent of the ZnO@NiO heterostructures (eightfold) when compared with that of the pure ZnO nanorods. Moreover, the high photodegradation efficiency of the ZnO@NiO heterostructures was maintained over three successive degradation experiments and decreased to 90% after the third cycle.

| S-EPMC6117222 | biostudies-literature

Characteristics of Gasless Combustion of Core-Shell Al@NiO Microparticles with Boosted Exothermic Performance.

Project description:The microstructures and thermochemical behavior of the energetic composites composed of core-shell structured μAl@NiO microparticles were characterized. These core-shell microparticles were synthesized using a wet-chemistry-based one-pot process, where the assembly was proposed to be driven by the electrostatic force between negatively charged Al and positively charged Ni-NH3 ions. Electron microscopic images demonstrated the formation of NiO nanoparticles adhering to the surface of microsized Al particles with different equivalence ratios. Thermal analysis revealed two consecutive exothermic peaks resulting from the initial thermite reaction between 890 and 960 °C and subsequently the intermetallic/alloy formation reactions between 1000 and 1040 °C. The latter was further confirmed by the endothermic peaks of Al-Ni alloy melting at higher temperatures. The formation of alloy was substantiated by the melting of AlNi3, AlNi, and Al3Ni. The onset temperature of the first exothermic peak decreased with increasing nominal equivalence ratio of the core-shell. Compared to the physically mixed (PM) composite, the core-shell structures decreased the activation energy of the thermite reaction by a mere 9.24 kJ/mol; however, it increased the combustibility by the manifold. The PM composite was not able to be ignited at all by a 5 W laser, while the core-shell counterpart ignited at 2.55 ms and was completely combusted within 6.50 ms accompanying a violent impulse.

| S-EPMC11359633 | biostudies-literature

Al13@Pt42 core-shell cluster for oxygen reduction reaction.

Project description:To increase Pt utilization for oxygen reduction reaction (ORR) in fuel cells, reducing particle sizes of Pt is a valid way. However, poisoning or surface oxidation limits the smallest size of Pt particles at 2.6 nm with a low utility of 20%. Here, using density functional theory calculations, we develop a core-shell Al13@Pt42 cluster as a catalyst for ORR. Benefit from alloying with Al in this cluster, the covalent Pt-Al bonding effectively activates the Pt atoms at the edge sites, enabling its high utility up to 70%. Valuably, the adsorption energy of O is located at the optimal range with 0.0-0.4 eV weaker than Pt(111), while OH-poisoning does not observed. Moreover, ORR comes from O2 dissociation mechanism where the rate-limiting step is located at OH formation from O and H with a barrier of 0.59 eV, comparable with 0.50 eV of OH formation from O and H2O on Pt(111).

| S-EPMC5381497 | biostudies-literature

Real-time detection of chlorine gas using Ni/Si shell/core nanowires.

Project description:We demonstrate the selective adsorption of Ni/Si shell/core nanowires (Ni-Si NWs) with a Ni outer shell and a Si inner core on molecularly patterned substrates and their application to sensors for the detection of chlorine gas, a toxic halogen gas. The molecularly patterned substrates consisted of polar SiO2 regions and nonpolar regions of self-assembled monolayers of octadecyltrichlorosilane (OTS). The NWs showed selective adsorption on the polar SiO2 regions, avoiding assembly on the nonpolar OTS regions. Utilizing these assembled Ni-Si NWs, we demonstrate a sensor for the detection of chlorine gas. The utilization of Ni-Si NWs resulted in a much larger sensor response of approximately 23% to 5 ppm of chlorine gas compared to bare Ni NWs, due to the increased surface-to-volume ratio of the Ni-Si shell/core structure. We expect that our sensor will be utilized in the future for the real-time detection of halogen gases including chlorine with high sensitivity and fast response.

| S-EPMC4314467 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data