ANOMALOUS TEMPERATURE-DEPENDENCE OF THE ELECTRICAL-RESISTIVITY IN BINARY AND PSEUDOBINARY ALLOYS BASED ON FE3SI

The electrical resistivity of binary Fe-Si and ternary (Fe1-xMx)3Si alloys' with 3d transition-metal elements M = Ti, V, Cr, Mn, Co, and Ni, has been measured over the temperature range from 4.2 to 1373 K. The resistivity for M = Ti, V, Cr, and Mn shows an anomalous temperature dependence: an occurrence Of a resistance maximum near the Curie point T(C) and a negative resistivity slope above T(C). The tendency of the negative temperature dependence of the resistivity increases markedly with increasing composition, accompanying a sharp reduction in T(C). In contrast, the resistivity curves for M = Co and Ni exhibit almost the same form as that of Fe3Si, regardless of the Co or Ni composition, so that the resistivity above T(C) remains almost constant or decreases slightly. The negative temperature dependence induced by M substitution appears only when the resistivity estimated in the paramagnetic state is above 150 muOMEGA cm, and the higher paramagnetic resistivity causes the lower temperature coefficient of the resistivity. It is concluded that the resistance maximum in (Fe1-xMx)3Si is closely related to an extremely large spin-disorder scattering, in addition to a high residual resistivity.