Magnetotransport properties of R2Fe14B compounds

Results of electrical resistivity and Hall effect measurements, obtained for R2Fe14B single crystals (R=Y, Nd, Gd and Tm), enable us to draw some general conclusions about the conduction processes in these materials. The overall behavior of the resistivity is determined by Fe atoms, although contributions from the rare-earth atoms are clearly observed at low temperatures. Large variations of the Hall resistivity found near the spin reorientation and Curie temperature can be attributed to critical magnetization fluctuations which enhance skew scattering in these regions. Away from the magnetic transition regions, the iron sublattice contributes mainly to the anomalous Hall resistivity. However, below the Curie temperature, the Hall effect arising from skew scattering is particularly large in Gd compound. A covalent mixing interaction is likely responsible for this behavior.