Magnetization and Magnetoresistance of MnSi. I

抄録

Magnetization and magnetoresistance of itinerant electron helical magnet MnSi has been studied down to 0.45 K. A large negative magnetoresistance is observed especially around Néel temperature T_N in accord with the theoretical expectation. Below 1 K, however, a positive magnetoresistance is found and it is attributed to the normal magnetoresistance due to impurity scattering. Anomalous peaks in the magnetization and magnetoresistance are observed just below T_N between about 1.0 and 2.2 kOe and the existence of two new phases are suggested.