Magnetic properties of cobalt‐carbon nanocomposites

Matsui, Denys; Prylutskyy, Yu. І.; Matzui, L. Yu.; Zakharenko, M.; Normand, F. Le; Derory, A.

doi:10.1002/pssc.200982963

Cited by 7 publications

(3 citation statements)

References 20 publications

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“…This makes the energy barrier of embedding a single TM atom into pristine graphene lattices very steep. Indeed, previous attempts to produce TM-graphene compositions merely yielded TM atoms or clusters adsorbed on the surface of graphene 25 , 26 , where the magnetism is not intrinsic but mainly contributed by the metal clusters. Meanwhile the adsorbed TM atoms on graphene could be easily dissociated or coagulated at elevated temperatures.…”

Section: Introductionmentioning

confidence: 99%

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

et al. 2021

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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 TC 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 pz 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.

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Section: Introductionmentioning

confidence: 99%

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

et al. 2021

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“…However, challenges persist in the realm of magnetic inorganic materials, particularly concerning large-scale synthesis and material stability under ambient conditions, necessitating further investigation . Apart from inorganic magnetic materials, alternative strategies have been proposed to induce magnetism into graphene by surface adsorption, − defects engineering, − proximity effect, and elemental atom doping. , Among these approaches, magnetic moments of graphene induced by molecular adsorption and point defects are typically vulnerable to thermal fluctuation and the chemical environment. − In addition, the proximity effect mainly relies on the fabrication of graphene/magnetic material heterostructures, which are constrained by sample size and require a specific thickness of the magnetic substrate . Therefore, doping graphene with elemental atoms, especially transition metal (TM) atoms, has been proposed as an effective way to achieve robust ferromagnetism with a relatively high Curie temperature. ,− TM atoms not only contribute magnetic moments but also introduce itinerant carriers into graphene, enhancing the ferromagnetic exchange coupling.…”

Section: Introductionmentioning

confidence: 99%

Air-Stable Wafer-Scale Ferromagnetic Metallo-Carbon Nitride Monolayer

Lyu,

Wang,

Guo

et al. 2024

J. Am. Chem. Soc.

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The pursuit of robust, long-range magnetic ordering in two-dimensional (2D) materials holds immense promise for driving technological advances. However, achieving this goal remains a grand challenge due to enhanced quantum and thermal fluctuations as well as chemical instability in the 2D limit. While magnetic ordering has been realized in atomically thin flakes of transition metal chalcogenides and metal halides, these materials often suffer from air instability. In contrast, 2D carbon-based materials are stable enough, yet the challenge lies in creating a high density of local magnetic moments and controlling their long-range magnetic ordering. Here, we report a novel wafer-scale synthesis of an air-stable metallo-carbon nitride monolayer (MCN, denoted as MN 4 /CN x ), featuring ultradense single magnetic atoms and exhibiting robust room-temperature ferromagnetism. Under low-pressure chemical vapor deposition conditions, thermal dehydrogenation and polymerization of metal phthalocyanine (MPc) on copper foil at elevated temperature generate a substantial number of nitrogen coordination sites for anchoring magnetic single atoms in monolayer MN 4 /CN x (where M = Fe, Co, and Ni). The incorporation of densely populating MN 4 sites into monolayer MCN networks leads to robust ferromagnetism up to room temperature, enabling the observation of anomalous Hall effects with excellent chemical stability. Detailed electronic structure calculations indicate that the presence of high-density metal sites results in the emergence of spin-split d-bands near the Fermi level, causing a favorable long-range ferromagnetic exchange coupling through direct exchange interactions. Our work demonstrates a novel synthesis approach for wafer-scale MCN monolayers with robust room-temperature ferromagnetism and may shed light on practical electronic and spintronic applications.

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“…Indeed, previous attempts to produce TM-graphene compositions merely yielded TM atoms or clusters adsorbed on the surface of graphene, 25,26 where the magnetism is not intrinsic but mainly contributed by metal clusters. Meanwhile the adsorbed TM atoms on graphene could be easily dissociated or coagulated at elevated temperatures.…”

Section: Introductionmentioning

confidence: 99%

Embedding atomic cobalt into graphene lattices to active room-temperature ferromagnetism

Wang

Tan

et al. 2020

Preprint

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Graphene is extremely promising for next-generation spintronics applications; however, realizing graphene-based room-temperature magnets remains a great challenge. Here, for the first time, we demonstrate that robust room-temperature ferromagnetism with TC up to ~400 K and saturation magnetization of 0.11 emu/g (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 d-p orbital hybridization between the embedded Co and matrix N/C atoms generates spin polarization for the delocalized N/C 2pz electrons and consequently enhances the long-range coupling through Stoner ferromagnetism. This work provides an effective means to induce room-temperature ferromagnetism in graphene and may open the possibilities for developing graphene-based spintronics devices.

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Magnetic properties of cobalt‐carbon nanocomposites

Cited by 7 publications

References 20 publications

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

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

Air-Stable Wafer-Scale Ferromagnetic Metallo-Carbon Nitride Monolayer

Embedding atomic cobalt into graphene lattices to active room-temperature ferromagnetism

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