抄録
The electrical resistivity and magnetoresistance of 1T-TaS2−xSex (x=0–0.4) have been measured from a few Kelvin to 30 mK. The resistivity follows a two dimensional variable range hopping process in the temperature range from a few Kelvin to 1 K and deviates upward at lower temperatures. On the other hand, the magnetoresistance is found to show positive and negative ones. The resistivity and the corresponding positive magnetoresistance become larger as the growth temperature of crystal becomes higher and/or as the doping amount of Se becomes more. Below about 0.1 K, only the negative magnetoresistance is observed. These results are qualitatively understood by taking into account the Zeeman effect of the electrons, suppression of hopping process by the magnetic field and also the magnetic order of the spins of the localized electrons.