@article{oai:muroran-it.repo.nii.ac.jp:00005819,
 author = {BURKOV, A. T. and NAKAMA, T. and HEDO, M. and SHINTANI, K. and YAGASAKI, K. and MATSUMOTO, N. and Nagata,  Shoichi and 永田, 正一},
 issue = {15},
 journal = {Physical review. Third series. B, Condensed matter and materials physics},
 month = {Apr},
 note = {application/pdf, Resistivity (ρ) and thermopower (S) of spinel-type compounds CuIr2S4 and CuIr2Se4 have been measured at temperatures from 2 to 900 K under magnetic field from 0 to 15 T. The thermopower is positive in the metallic phase of both compounds at high temperatures, as well as in the low-temperature insulating state of CuIr2S4. The positive thermopower of the insulating phase implies p-type charge carriers, in agreement with the recent photoemission results. The low-temperature resistivity of CuIr2S4 is in good agreement with the Efros-Shklovskii variable-range hopping conductivity mechanism: ρ=ρ0exp[(T*/T)1/2]. The most striking result is that the resistivity of the metallic phases is well described by an exponential-type temperature dependence in a wide temperature range from 2 K to at least 900 K. This unusual result for metals type of the resistivity temperature dependence, as well as other features in the transport properties, imply a nonconventional conductivity mechanism. The magnetoresistivity Δρ is positive and proportional to H2, while magnetothermopower ΔS=S(H,T)-S(0,T) is very small for both compounds at all temperatures},
 pages = {10049--10056},
 title = {Anomalous resistivity and thermopower of the spinel-type compounds CuIr2S4 and CuIr2Se4},
 volume = {61},
 year = {2000},
 yomi = {ナガタ, ショウイチ}
}