ELECTRON-TRANSPORT PROPERTIES OF R(2)FE(14)B COMPOUNDS

The electrical resistivity of R(2)Fe(14)B (R=lanthanide series) polycr pstalline samples was measured over the temperature range of 4-700 K. Even though the overall behavior of the resistivity in R(2)Fe(14)B is determined mainly by Fe atoms, interesting features follow from the pr esence of rare-earth atoms. At low temperatures, the resistivity rho i ncreases with temperature as T-2. We find that scattering of electrons by modes involving all spins, with a dispersion given by the R-Fe exc hange interaction, contributes to this behavior. On the other hand, th e high-temperature anomaly in rho observed just below the Curie temper ature is quite likely produced by electronphonon scattering arising fr om a pronounced lattice softening in this temperature region. Saturati on values of the high-temperature magnetic resistivity are in agreemen t with de Gennes and Friedel's prediction for spin-disorder scattering .