Fermi Surface and Magnetic Properties in Ferromagnet CoS<sub>2</sub>and Paramagnet CoSe<sub>2</sub>with the Pyrite-type Cubic Structure

Teruya, Atsushi; Suzuki, Fuminori; Aoki, Dai; Honda, Fuminori; Nakamura, Ai; Nakashima, Miho; Amako, Yasushi; Harima, Hisatomo; Uchima, Kiyoharu; Hedo, Masato; Nakama, Takao; Ōnuki, Yoshichika

doi:10.1088/1742-6596/807/1/012001

Cited by 16 publications

(12 citation statements)

References 14 publications

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“…A few studies have been conducted on the preparation and application of CoX 2 . For example, a nonlayered material CoS 2 is reported as ferromagnetic metal with the Curie temperature T C of 124 K, and CoSe 2 with the pyrite-type structure is regarded as the controversial Pauli paramagnet or the antiferromagnet. − Some initial efforts have also been made on CoTe 2 in two dimensions recently. Duan and co-workers reported the layer-controlled growth of CoTe 2 and CoSe and studied the electric properties of the resulting nanosheets. , Wang and co-workers found tunable magnetic properties of CoTe 2 treated with different concentrations of NaOH .…”

Section: Introductionmentioning

confidence: 99%

Thickness-Controlled Synthesis of CoX₂ (X = S, Se, and Te) Single Crystalline 2D Layers with Linear Magnetoresistance and High Conductivity

et al. 2020

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Two-dimensional (2D) materials especially transition metal dichalcogenides (TMDs) have drawn intensive interest owing to their plentiful properties. Some TMDs with magnetic elements (Fe, Co, Ni, etc.) are reported to be magnetic theoretically and experimentally, which undoubtedly provide a promising platform to design functional devices and study physical mechanisms. Nevertheless, plenty of theoretical TMDs remain unrealized experimentally. In addition, the governable synthesis of these kinds of TMDs with desired thickness and high crystallinity poses a tricky challenge. Here, we report a controlled preparation of CoX2 (X = S, Se, and Te) nanosheets through chemical vapor deposition. The thickness, lateral scale, and shape of the crystals show great dependence on temperature, and the thickness can be controlled from a monolayer to tens of nanometers. Magneto-transport characterization and density function theory simulation indicate that CoSe2 and CoTe2 are metallic. In addition, unsaturated and linear magnetoresistance have been observed even up to 9 T. The conductivity of CoSe2 and CoTe2 can reach 5 × 106 and 1.8 × 106 S/m, respectively, which is pretty high and even comparable with silver. These cobalt-based TMDs show great potential to work as 2D conductors and also provide a promising platform for investigating their magnetic properties.

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Section: Introductionmentioning

confidence: 99%

Thickness-Controlled Synthesis of CoX₂ (X = S, Se, and Te) Single Crystalline 2D Layers with Linear Magnetoresistance and High Conductivity

et al. 2020

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“…Correspondingly, the electric specific heat coefficient γ = 21 mJ/(K 2 ・mol) in CoS 2 decreases linearly to γ = 18 mJ/(K 2 ・mol) in CoSe 2 with increasing the Se concentration x. [5] These facts can be reasonably understood by the degree of the bandwidth of 3d-e g band. Since the hybridization between the 3d-e g and p * states in CoSe 2 is stronger than that in CoS 2 , the increase of x makes the bandwidth wider in Co(S 1-x Se x ) 2 .…”

Section: Introductionmentioning

confidence: 75%

“…The 3d-e g states are hybridized with the antibonding p * states arising from the S pairs. CoS 2 is a ferromagnet with a Curie temperature T C of 122 K with the fractional magnetic moment of µ s = 0.93 µ B /Co [5,6]. In the substitution of S with Se, Co(S 1-x Se x ) 2 system, in which the larger atomic size of Se results in an expansion of the lattice, one can find a rapid decrease of T C by the substitution of Se for S. [2] The system shows finally the disappearance of ferromagnetism and becomes an exchanged-enhanced Pauli paramagnet near x ~ 0.12, implying possible existence of a quantum critical point (QCP).…”

Section: Introductionmentioning

confidence: 99%

“…Furthermore, the recent de Haas-van Alphen experiment indicates that the main Fermi surface of CoS 2 is a half-metallic spin polarized state and possesses a large cyclotron effective mass of 13 m 0 . [5] It is well-known that ultrasound is well suited to elucidate the nature of an ordered phase, even magnetic one via spin-lattice coupling. In this paper, we discuss the elastic property, and also the possible nature of the newly observed elastic anomaly in the ferromagnetic state of CoS 2 .…”

Section: Introductionmentioning

confidence: 99%

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Elastic Anomalies of the Half-metallic Itinerant Ferromagnet CoS₂ Associated with Magnetic Phase Transition

Kudo

Nakamura

et al. 2020

Proceedings of the International Conference on Strongly Correlated Electron Systems (SCES2019)

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Elastic properties of the half-metallic itinerant ferromagnet CoS 2 have been investigated by means of ultrasonic measurement. A pronounced precursor elastic anomaly towards T C was observed in the temperature dependence of elastic modes, probably associated with the ferromagnetic long-range order. The precursor elastic anomaly, however shifts to upper temperatures and becomes smeared upon increasing a magnetic field, in good agreement with the previously determined phase diagram of CoS 2. Results for the longitudinal elastic mode C L show a particular behavior at low temperatures. For further cooling, another slight elastic anomaly can be recognized around 100 K, far below T C. Data analysis of deformation potential approximation suggests that a coupling constant between a strain tensor and relevant quasiparticle bands with heavy masses near the Fermi level would be fairly large. We discuss the elastic property, and also the nature of the novel elastic anomaly observed in the magnetically ordered state of CoS 2 .

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“…Cobalt chalcogenides are also promising candidates for 2D magnets with multiple structural phases. CoS 2 and CoSe 2 are pyrite‐type cubic compounds, and CoS 2 is a ferromagnetic metal with T c of 124 K, whereas CoSe 2 is either a Pauli paramagnet or antiferromagnet 76,77 . Ultrathin CoX 2 crystals have been successfully fabricated by CVD, and the thickness can be controlled from a ML to tens of nanometers 78 .…”

Section: Intrinsic Magnetism In 2d Tmcsmentioning

confidence: 99%

Two‐dimensional magnetic transition metal chalcogenides

2021

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The field of two‐dimensional (2D) magnets has expanded rapidly during the past several years since the first demonstration of intrinsic 2D magnetism in atomically thin CrI3 and Cr2Ge2Te6 in 2017. 2D transition metal chalcogenides (TMCs), a class of strongly correlated materials, have exhibited a wide variety of novel electronic and optical properties, and more recently magnetism. Here, we review recent experimental progress achieved in the growth of 2D magnetic TMC materials using chemical vapor deposition and molecular beam epitaxy methods. Outstanding examples include the demonstration of room temperature intrinsic and extrinsic ferromagnetism in monolayer VSe2, MnSe2, Cr3Te4, V‐doped WSe2, and so on. A brief discussion on the origin of the exotic magnetic properties and emergent phenomena is also presented. Finally, we summarize the remaining challenges and future perspective on the development of 2D magnetic materials for next‐generation spintronic devices.

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Fermi Surface and Magnetic Properties in Ferromagnet CoS₂and Paramagnet CoSe₂with the Pyrite-type Cubic Structure

Cited by 16 publications

References 14 publications

Thickness-Controlled Synthesis of CoX₂ (X = S, Se, and Te) Single Crystalline 2D Layers with Linear Magnetoresistance and High Conductivity

Thickness-Controlled Synthesis of CoX₂ (X = S, Se, and Te) Single Crystalline 2D Layers with Linear Magnetoresistance and High Conductivity

Elastic Anomalies of the Half-metallic Itinerant Ferromagnet CoS₂ Associated with Magnetic Phase Transition

Two‐dimensional magnetic transition metal chalcogenides

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Fermi Surface and Magnetic Properties in Ferromagnet CoS2and Paramagnet CoSe2with the Pyrite-type Cubic Structure

Cited by 16 publications

References 14 publications

Thickness-Controlled Synthesis of CoX2 (X = S, Se, and Te) Single Crystalline 2D Layers with Linear Magnetoresistance and High Conductivity

Thickness-Controlled Synthesis of CoX2 (X = S, Se, and Te) Single Crystalline 2D Layers with Linear Magnetoresistance and High Conductivity

Elastic Anomalies of the Half-metallic Itinerant Ferromagnet CoS2 Associated with Magnetic Phase Transition

Two‐dimensional magnetic transition metal chalcogenides

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Product

Resources

About

Fermi Surface and Magnetic Properties in Ferromagnet CoS₂and Paramagnet CoSe₂with the Pyrite-type Cubic Structure

Thickness-Controlled Synthesis of CoX₂ (X = S, Se, and Te) Single Crystalline 2D Layers with Linear Magnetoresistance and High Conductivity

Thickness-Controlled Synthesis of CoX₂ (X = S, Se, and Te) Single Crystalline 2D Layers with Linear Magnetoresistance and High Conductivity

Elastic Anomalies of the Half-metallic Itinerant Ferromagnet CoS₂ Associated with Magnetic Phase Transition