TY - JOUR
T1 - Fermi Surface and Magnetic Properties in Ferromagnet CoS2 and Paramagnet CoSe2 with the Pyrite-type Cubic Structure
AU - Teruya, A.
AU - Suzuki, F.
AU - Aoki, D.
AU - Honda, F.
AU - Nakamura, A.
AU - Nakashima, M.
AU - Amako, Y.
AU - Harima, H.
AU - Uchima, K.
AU - Hedo, M.
AU - Nakama, T.
AU - Onuki, Y.
N1 - Funding Information:
This work was supported by JSPS KAKENHI Grant Numbers 15H05884, 25247055, and 15H05886.
Publisher Copyright:
© Published under licence by IOP Publishing Ltd.
PY - 2017/4/6
Y1 - 2017/4/6
N2 - We succeeded in growing high-quality single crystals of pyrite-type cubic compounds CoSe2 and CoS2 using a transport agent of CoBr2 and measured the electrical resistivity, specific heat, magnetic susceptibility, magnetization, and the 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 T C = 122 K and an ordered moment μs = 0.93 μB/Co. The γ value of 21 mJ/(K2•mol) in CoS2 is slightly larger than that of CoSe2. A large ordered moment, together with a large γ value, is a characteristic feature in 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 13m 0 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 four-fold-symmetry in the angular dependence of the dHvA frequency.
AB - We succeeded in growing high-quality single crystals of pyrite-type cubic compounds CoSe2 and CoS2 using a transport agent of CoBr2 and measured the electrical resistivity, specific heat, magnetic susceptibility, magnetization, and the 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 T C = 122 K and an ordered moment μs = 0.93 μB/Co. The γ value of 21 mJ/(K2•mol) in CoS2 is slightly larger than that of CoSe2. A large ordered moment, together with a large γ value, is a characteristic feature in 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 13m 0 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 four-fold-symmetry in the angular dependence of the dHvA frequency.
UR - http://www.scopus.com/inward/record.url?scp=85018319654&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85018319654&partnerID=8YFLogxK
U2 - 10.1088/1742-6596/807/1/012001
DO - 10.1088/1742-6596/807/1/012001
M3 - Conference article
AN - SCOPUS:85018319654
SN - 1742-6588
VL - 807
JO - Journal of Physics: Conference Series
JF - Journal of Physics: Conference Series
IS - 1
M1 - 012001
T2 - 18th International Conference on Strongly Correlated Electron Systems, SCES 2016
Y2 - 9 May 2016 through 13 May 2016
ER -