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 al loys' 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 d ependence: 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). I n contrast, the resistivity curves for M = Co and Ni exhibit almost th e same form as that of Fe3Si, regardless of the Co or Ni composition, so that the resistivity above T(C) remains almost constant or decrease s slightly. The negative temperature dependence induced by M substitut ion appears only when the resistivity estimated in the paramagnetic st ate is above 150 muOMEGA cm, and the higher paramagnetic resistivity c auses the lower temperature coefficient of the resistivity. It is conc luded that the resistance maximum in (Fe1-xMx)3Si is closely related t o an extremely large spin-disorder scattering, in addition to a high r esidual resistivity.