Abstract

The textured polycrystalline Bi_95.69Mn_3.69Fe_0.62 containing two phases: the bismuth matrix and the α-BiMn phase inclusions, was studied. It is shown that the anomalous behavior of the temperature dependences of the magnetization can be associated with a reorientational transition of the magnetic moments of Mn in the α-BiMn phase due to a change in the sign of the magnetic anisotropy constant. It is established that in the magnetic field the temperature dependences of the electrical resistivity behave nonmonotonically, and the magnetoresistance is positive in the entire temperature range and reaches a maximum value of 3033% in a magnetic field of 140 kOe for orientation, when the magnetic field is perpendicular to the transport current. A strong anisotropy of the electrical resistivity is revealed in measurements in the magnetic field. It is assumed that the anomalous behavior of the electrical resistivity temperature dependences as compared to are related to change the degree of overlapping between electron and hole regions of the Fermi surface under the influence of the α-BiMn phase magnetism, as well as the magnitude and direction of the external magnetic field.

Key words: magnetoresistance, anisotropy of electrical resistance, reorientation transition, spin glass, electron and hole regions of the Fermi surface, α-BiMn phase, bismuth.