Large cyclotron mass and large ordered moment in ferromagnet CoS2 compared with paramagnet CoSe2

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

Research output: Contribution to journalArticlepeer-review

7 Citations (Scopus)

Abstract

We succeeded in growing high-quality single crystals of the pyrite-type cubic compounds CoSe2 and CoS2 using the transport agent CoBr2 and measured the electrical resistivity, specific heat, magnetic susceptibility, magnetization, and de Haas-van Alphen (dHvA) effect. We confirmed that CoSe2 is an exchange-enhanced paramagnet revealing a broad maximum at around 50 K in the temperature dependence of the magnetic susceptibility. The electronic specific heat coefficient is moderately large, γ = 18 mJ=(K2·mol). On the other hand, CoS2 is a ferromagnet with a Curie temperature TC = 122 K and an ordered moment μs = 0.93 μB/Co. The γ of 21 mJ=(K2·mol) of CoS2 is slightly larger than that of CoSe2. A large ordered moment, together with a large γ, is characteristic of CoS2 because CoS2 is a half-metallic spin state in the ferromagnetic state. Correspondingly, we detected a main dHvA branch with a large cyclotron effective mass of 13m0 in the dHvA experiments. The detected dHvA branches in CoS2 and CoSe2 are discussed on the basis of the results of energy band calculations, revealing a broken fourfold symmetry in the angular dependence of the dHvA frequency.

Original languageEnglish
Article number064716
Journaljournal of the physical society of japan
Volume85
Issue number6
DOIs
Publication statusPublished - Jun 15 2016
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)

Fingerprint Dive into the research topics of 'Large cyclotron mass and large ordered moment in ferromagnet CoS<sub>2</sub> compared with paramagnet CoSe<sub>2</sub>'. Together they form a unique fingerprint.

Cite this