Browse
Submit Data
Databases
API
Help

Dataset Information

28 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Embedding atomic cobalt into graphene lattices to activate room-temperature ferromagnetism.

ABSTRACT: Graphene is extremely promising for next-generation spintronics applications; however, realizing graphene-based room-temperature magnets remains a great challenge. Here, we demonstrate that robust room-temperature ferromagnetism with T_C up to ∼400 K and saturation magnetization of 0.11 emu g^-1 (300 K) can be achieved in graphene by embedding isolated Co atoms with the aid of coordinated N atoms. Extensive structural characterizations show that square-planar Co-N₄ moieties were formed in the graphene lattices, where atomically dispersed Co atoms provide local magnetic moments. Detailed electronic structure calculations reveal that the hybridization between the d electrons of Co atoms and delocalized p_z electrons of N/C atoms enhances the conduction-electron mediated long-range magnetic coupling. This work provides an effective means to induce room-temperature ferromagnetism in graphene and may open possibilities for developing graphene-based spintronics devices.

SUBMITTER: Hu W

PROVIDER: S-EPMC7994802 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Tuning ferromagnetism at room temperature by visible light.

Project description:Most digital information today is encoded in the magnetization of ferromagnetic domains. The demand for ever-increasing storage space fuels continuous research for energy-efficient manipulation of magnetism at smaller and smaller length scales. Writing a bit is usually achieved by rotating the magnetization of domains of the magnetic medium, which relies on effective magnetic fields. An alternative approach is to change the magnetic state directly by acting on the interaction between magnetic moments. Correlated oxides are ideal materials for this because the effects of a small external control parameter are amplified by the electronic correlations. Here, we present a radical method for reversible, light-induced tuning of ferromagnetism at room temperature using a halide perovskite/oxide perovskite heterostructure. We demonstrate that photoinduced charge carriers from the [Formula: see text] photovoltaic perovskite efficiently dope the thin [Formula: see text] film and decrease the magnetization of the ferromagnetic state, allowing rapid rewriting of the magnetic bit. This manipulation could be accomplished at room temperature; hence this opens avenues for magnetooptical memory devices.

| S-EPMC7104399 | biostudies-literature

Disorder-induced room temperature ferromagnetism in glassy chromites.

Project description:We report an unusual robust ferromagnetic order above room temperature upon amorphization of perovskite [YCrO3] in pulsed laser deposited thin films. This is contrary to the usual expected formation of a spin glass magnetic state in the resulting disordered structure. To understand the underlying physics of this phenomenon, we combine advanced spectroscopic techniques and first-principles calculations. We find that the observed order-disorder transformation is accompanied by an insulator-metal transition arising from a wide distribution of Cr-O-Cr bond angles and the consequent metallization through free carriers. Similar results also found in YbCrO3-films suggest that the observed phenomenon is more general and should, in principle, apply to a wider range of oxide systems. The ability to tailor ferromagnetic order above room temperature in oxide materials opens up many possibilities for novel technological applications of this counter intuitive effect.

| S-EPMC3986702 | biostudies-other

A polar corundum oxide displaying weak ferromagnetism at room temperature.

Project description:Combining long-range magnetic order with polarity in the same structure is a prerequisite for the design of (magnetoelectric) multiferroic materials. There are now several demonstrated strategies to achieve this goal, but retaining magnetic order above room temperature remains a difficult target. Iron oxides in the +3 oxidation state have high magnetic ordering temperatures due to the size of the coupled moments. Here we prepare and characterize ScFeO(3) (SFO), which under pressure and in strain-stabilized thin films adopts a polar variant of the corundum structure, one of the archetypal binary oxide structures. Polar corundum ScFeO(3) has a weak ferromagnetic ground state below 356 K-this is in contrast to the purely antiferromagnetic ground state adopted by the well-studied ferroelectric BiFeO(3).

| S-EPMC3693400 | biostudies-literature

Realization of ground-state artificial skyrmion lattices at room temperature.

Project description:The topological nature of magnetic skyrmions leads to extraordinary properties that provide new insights into fundamental problems of magnetism and exciting potentials for novel magnetic technologies. Prerequisite are systems exhibiting skyrmion lattices at ambient conditions, which have been elusive so far. Here, we demonstrate the realization of artificial Bloch skyrmion lattices over extended areas in their ground state at room temperature by patterning asymmetric magnetic nanodots with controlled circularity on an underlayer with perpendicular magnetic anisotropy (PMA). Polarity is controlled by a tailored magnetic field sequence and demonstrated in magnetometry measurements. The vortex structure is imprinted from the dots into the interfacial region of the underlayer via suppression of the PMA by a critical ion-irradiation step. The imprinted skyrmion lattices are identified directly with polarized neutron reflectometry and confirmed by magnetoresistance measurements. Our results demonstrate an exciting platform to explore room-temperature ground-state skyrmion lattices.

| S-EPMC4633628 | biostudies-literature

Microscopic origins for stabilizing room-temperature ferromagnetism in ultrathin manganite layers.

Project description:La(0.7)Sr(0.3)MnO(3) is a conducting ferromagnet at room temperature. Combined with thin SrTiO(3) layers, the resulting heterostructures could be used as highly spin-polarized magnetic-tunnel-junction memories. However, when shrunk to dimensions below an apparent critical thickness, the structures become insulating and ferromagnetic ordering is suppressed. Interface spin and charge modulations are thought to create an interfacial dead layer, thus fundamentally limiting the use of this material in atomic-scale devices. The thickness of this dead layer, and whether it is intrinsic, is still controversial. Here we use atomic-resolution electron spectroscopy to demonstrate that the degradation of the magnetic and transport properties of La(0.7)Sr(0.3)MnO(3)/SrTiO(3) multilayers correlates with atomic intermixing at the interfaces, and the presence of extended two-dimensional cation defects in the La(0.7)Sr(0.3)MnO(3) layers (in contrast to three-dimensional precipitates in thick films). When these extrinsic defects are eliminated, metallic ferromagnetism at room temperature can be stabilized in five-unit-cell-thick manganite layers in superlattices, placing the upper limit for any intrinsic dead layer at two unit cells per interface.

| S-EPMC2900658 | biostudies-literature

Room Temperature Ferromagnetism in InGaN Nanostructures Induced by Cr+ ion Implantation.

Project description:This paper presents the magnetic properties of chrome ion (Cr+) implanted InxGa1-xN (x = 0.1, 0.3, 0.5 and 1.0) nanostructures grown by molecular beam epitaxy (MBE). The Cr+ implantation was conducted at 110 keV with three doses, namely 2.6 × 1015, 5.3 × 1015, and 1.3 × 1016 ions/cm2. The as-grown nanostructures exhibited diamagnetism before and after ion implantation without annealing. However, after annealing, the nanostructures exhibited ferromagnetism at room temperature. The saturation magnetization (Ms) and coercive force (Hc) increase with increasing Cr+ dose. The Ms of the InN nanorods with diameters of 100-160 nm is larger than that of those with small diameters of 60-80 nm. For InGaN nanostructures, the indium concentration-that is, the band structure-is more important than the diameters of the nanorods for the same doping level of Cr ions. The Ms of InGaN nanorods with an indium concentration of 10% reaches its maximum. The zero-field cooled (ZFC) and field-cooled (FC) curves show that nanostructures have no parasitic magnetic phases.

| S-EPMC7353168 | biostudies-literature

Room-temperature intrinsic ferromagnetism in epitaxial CrTe<sub>2</sub> ultrathin films.

Project description:While the discovery of two-dimensional (2D) magnets opens the door for fundamental physics and next-generation spintronics, it is technically challenging to achieve the room-temperature ferromagnetic (FM) order in a way compatible with potential device applications. Here, we report the growth and properties of single- and few-layer CrTe2, a van der Waals (vdW) material, on bilayer graphene by molecular beam epitaxy (MBE). Intrinsic ferromagnetism with a Curie temperature (TC) up to 300 K, an atomic magnetic moment of ~0.21 [Formula: see text]/Cr and perpendicular magnetic anisotropy (PMA) constant (Ku) of 4.89 × 105 erg/cm3 at room temperature in these few-monolayer films have been unambiguously evidenced by superconducting quantum interference device and X-ray magnetic circular dichroism. This intrinsic ferromagnetism has also been identified by the splitting of majority and minority band dispersions with ~0.2 eV at Г point using angle-resolved photoemission spectroscopy. The FM order is preserved with the film thickness down to a monolayer (TC ~ 200 K), benefiting from the strong PMA and weak interlayer coupling. The successful MBE growth of 2D FM CrTe2 films with room-temperature ferromagnetism opens a new avenue for developing large-scale 2D magnet-based spintronics devices.

| S-EPMC8093203 | biostudies-literature

Atomic cobalt as an efficient electrocatalyst in sulfur cathodes for superior room-temperature sodium-sulfur batteries.

Project description:The low-cost room-temperature sodium-sulfur battery system is arousing extensive interest owing to its promise for large-scale applications. Although significant efforts have been made, resolving low sulfur reaction activity and severe polysulfide dissolution remains challenging. Here, a sulfur host comprised of atomic cobalt-decorated hollow carbon nanospheres is synthesized to enhance sulfur reactivity and to electrocatalytically reduce polysulfide into the final product, sodium sulfide. The constructed sulfur cathode delivers an initial reversible capacity of 1081?mA?h?g-1 with 64.7% sulfur utilization rate; significantly, the cell retained a high reversible capacity of 508?mA?h?g-1 at 100?mA?g-1 after 600 cycles. An excellent rate capability is achieved with an average capacity of 220.3?mA?h?g-1 at the high current density of 5?A?g-1. Moreover, the electrocatalytic effects of atomic cobalt are clearly evidenced by operando Raman spectroscopy, synchrotron X-ray diffraction, and density functional theory.

| S-EPMC6172263 | biostudies-other

Room-temperature magnetic ordering in functionalized graphene.

Project description:Despite theoretical predictions, the question of room-temperature magnetic order in graphene must be conclusively resolved before graphene can fully achieve its potential as a spintronic medium. Through scanning tunneling microscopy (STM) and point I-V measurements, the current study reveals that unlike pristine samples, graphene nanostructures, when functionalized with aryl radicals, can sustain magnetic order. STM images show 1-D and 2-D periodic super-lattices originating from the functionalization of a single sub-lattice of the bipartite graphene structure. Field-dependent super-lattices in 3-nm wide "zigzag" nanoribbons indicate local moments with parallel and anti-parallel ordering along and across the edges, respectively. Anti-parallel ordering is observed in 2-D segments with sizes of over 20 nm. The field dependence of STM images and point I-V curves indicates a spin polarized local density of states (LDOS), an out-of-plane anisotropy field of less than 10 Oe, and an exchange coupling field of 100 Oe at room temperature.

| S-EPMC3432455 | biostudies-literature

Nearly room temperature ferromagnetism in a magnetic metal-rich van der Waals metal.

Project description:In spintronics, two-dimensional van der Waals crystals constitute a most promising material class for long-distance spin transport or effective spin manipulation at room temperature. To realize all-vdW-material-based spintronic devices, however, vdW materials with itinerant ferromagnetism at room temperature are needed for spin current generation and thereby serve as an effective spin source. We report theoretical design and experimental realization of a iron-based vdW material, Fe4GeTe2, showing a nearly room temperature ferromagnetic order, together with a large magnetization and high conductivity. These properties are well retained even in cleaved crystals down to seven layers, with notable improvement in perpendicular magnetic anisotropy. Our findings highlight Fe4GeTe2 and its nanometer-thick crystals as a promising candidate for spin source operation at nearly room temperature and hold promise to further increase T c in vdW ferromagnets by theory-guided material discovery.

| S-EPMC6968938 | 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