Large Cyclotron Mass and Large Ordered Moment in Ferromagnet CoS<sub>2</sub> Compared with Paramagnet CoSe<sub>2</sub>

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

doi:10.7566/jpsj.85.064716

Cited by 13 publications

(12 citation statements)

References 27 publications

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“…−1 , corresponding to a bare density of states of N (E F ) = 3γ/(π 2 k 2 B ) = 13.6 states/eV/f.u., consistent with the electronic structure calculation [27]. Note that the Sommerfeld constant of CoS 2 is 21 mJ K −2 mol −1 [24,25], somewhat smaller than the above γ value, yet it turns out to be larger on the basis of Co content. Furthermore, the CoS 2 impurity is the minor phase after all.…”

Section: Resultssupporting

confidence: 84%

“…The synthesized sample tends to form CoS 2 impurity, as revealed by the phaserelation study in the Cu-Co-S system [20,21]. Indeed, later studies [12,[14][15][16] also showed presence of the CoS 2 impurity for the reaction temperatures from 500 • C to 800 • C. Note that CoS 2 is a ferromagnet with a Curie temperature of ∼120 K [23][24][25], which makes it more easily to be detected by the magnetic measurement [15].…”

Section: Introductionmentioning

confidence: 99%

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Bulk superconductivity and Pauli paramagnetism in nearly stoichiometric CuCo$_2$S$_4$

Jin,

Sun,

Cui

et al. 2021

Preprint

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It has long remained elusive whether CuCo2S4 thiospinel shows bulk superconductivity. Here we clarify the issue by studying on the samples of sulfur-deficient CuCo2S3.7 and sulfurized CuCo2S4. The sample CuCo2S3.7 has a smaller lattice constant of a = 9.454 Å, and it is not superconducting down to 1.8 K. After a full sulfurization, the a axis of the thiospinel phase increases to 9.475 Å, and the thiospinel becomes nearly stoichiometric CuCo2S4, although a secondary phase of slightly Cu-doped CoS2 forms. Bulk superconductivity at 4.2 K and Pauli paramagnetism have been demonstrated for the sulfurized CuCo2S4 by the measurements of electrical resistivity, magnetic susceptibility, and specific heat.

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Section: Resultssupporting

confidence: 84%

Section: Introductionmentioning

confidence: 99%

Bulk superconductivity and Pauli paramagnetism in nearly stoichiometric CuCo$_2$S$_4$

Jin,

Sun,

Cui

et al. 2021

Preprint

View full text Add to dashboard Cite

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“…vanishing minority-spin DOS at EF) due to the depopulation of a minority-spin electron pocket [16][17][18][19][20] . On the other hand, calculations based on the generalized gradient approximation (GGA) 15,21 (see Fig. 1B-C) conclude that half-metallicity is already obtained in the undoped compound, and quantum oscillation experiments were unable to detect the putative minority-spin electron pocket 21 .…”

Section: Main Textmentioning

confidence: 99%

Weyl fermions, Fermi arcs, and minority-spin carriers in ferromagnetic CoS ₂

et al. 2020

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Magnetic Weyl semimetals are a newly discovered class of topological materials that may serve as a platform for exotic phenomena, such as axion insulators or the quantum anomalous Hall effect. Here, we use angle-resolved photoelectron spectroscopy and ab initio calculations to discover Weyl cones in CoS2, a ferromagnet with pyrite structure that has been long studied as a candidate for half-metallicity, which makes it an attractive material for spintronic devices. We directly observe the topological Fermi arc surface states that link the Weyl nodes, which will influence the performance of CoS2 as a spin injector by modifying its spin polarization at interfaces. In addition, we directly observe a minority-spin bulk electron pocket in the corner of the Brillouin zone, which proves that CoS2 cannot be a true half-metal.

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“…The small curvature of the cubelike Fermi surface renders pyrite-type PdS2 a strong candidate to produce quantum oscillations and large effective mass. [63,64] Recently, the superconducting instability has been proposed to interplay with the topological nontrivial states. [65,66] Electronic band structure calculations speculate that the superconducting states originating from the Dirac and nodal-line states in the vicinity of the Fermi level in the high-pressure pyrite-type PdSe2.…”

Section: The Metallization Of Orthorhombic Phase Under Compression An...mentioning

confidence: 99%

Structural transition, metallization, and superconductivity in quasi-two-dimensional layered PdS2 under compression

et al. 2020

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Based on first-principles simulations and calculations, we explore the evolutions of crystal structure, electronic structure and transport properties of quasi 2D layered PdS2 under compression by uniaxial stress and hydrostatic pressure. An interesting ferroelastic phase transition with lattice reorientation is revealed under uniaxial compressive stress, which originates from the bond reconstructions of the unusual PdS4 square-planar coordination. By contrast, the layered structure transforms to a 3D cubic pyrite-type structure under hydrostatic pressure. In contrary to the experimental proposed coexistence of layered PdS2-type structure with cubic pyrite-type structure at intermediate pressure range, we predict that the compression-induced intermediate phase showing the same structure symmetry with the ambient phase, except of sharply shrinking interlayer-distances. The coordination of the Pd ions not only plays crucial roles in the structural transition, but also lead to electronic structure and transport properties variations, which changes from square-planar to distorted octahedron in the intermediate phase, resulting in bandwidth broaden and orbital-selective metallization. In addition, the superconductivity in the cubic pyrite-type structure comes from the strong electron-phonon coupling in presence of topological nodal-line states. The strong interplay between structural transition, metallization and superconductivity in PdS2 provide a good platform to study the fundamental physics of the interactions between crystal structure and transport behavior, and the competition or cooperation between diverse phases.

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Large Cyclotron Mass and Large Ordered Moment in Ferromagnet CoS₂ Compared with Paramagnet CoSe₂

Cited by 13 publications

References 27 publications

Bulk superconductivity and Pauli paramagnetism in nearly stoichiometric CuCo$_2$S$_4$

Bulk superconductivity and Pauli paramagnetism in nearly stoichiometric CuCo$_2$S$_4$

Weyl fermions, Fermi arcs, and minority-spin carriers in ferromagnetic CoS ₂

Structural transition, metallization, and superconductivity in quasi-two-dimensional layered PdS2 under compression

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Large Cyclotron Mass and Large Ordered Moment in Ferromagnet CoS2 Compared with Paramagnet CoSe2

Cited by 13 publications

References 27 publications

Bulk superconductivity and Pauli paramagnetism in nearly stoichiometric CuCo$_2$S$_4$

Bulk superconductivity and Pauli paramagnetism in nearly stoichiometric CuCo$_2$S$_4$

Weyl fermions, Fermi arcs, and minority-spin carriers in ferromagnetic CoS 2

Structural transition, metallization, and superconductivity in quasi-two-dimensional layered PdS2 under compression

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Product

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Large Cyclotron Mass and Large Ordered Moment in Ferromagnet CoS₂ Compared with Paramagnet CoSe₂

Weyl fermions, Fermi arcs, and minority-spin carriers in ferromagnetic CoS ₂