Magnetotransport properties of Nd2Fe14B

The electrical resistivity and Hall effect of a single crystal of Nd2Fe14B have been measured over the temperature range of 10 to 300 K in magnetic fields of up to 12 T. At low temperature, a positive ~both transverse and longitudinal! magnetoresistance is observed. It can be attributed to scattering of carriers by magnetization-dependent mechanisms. The magnetoresistance decreases strongly with increasing temperature as the suppression of spin fluctuations by an external field becomes more important. Hall resistivity data are holelike and follow the magnetization of the material. The low-field Hall resistivity peaks at about 130 K, in the vicinity of the spin-reorientation temperature in Nd2Fe14B. Away from the peak, the Hall resistivity is proportional to the square of the total resistivity. We find that both skew scattering and side-jump scattering contribute to the Hall effect. However, spin fluctuations are important only in a small region close to the spin-reorientation temperature whereas side-jump scattering governs the Hall effect in the whole temperature range studied.
This work was supported by Project MAT 96-448 of Comision Interministerial de Ciencia y Tecnologia (CICYT).