Abstract
The electrical resistivity and Hall effect of ${\mathrm{Y}}_{2}{\mathrm{Fe}}_{14}\mathrm{B}$ single crystals have been measured over the temperature range of 4--700 K in magnetic fields of up to 5 T. From these and previous results, which we obtained for ${\mathrm{Nd}}_{2}{\mathrm{Fe}}_{14}\mathrm{B}$ and ${\mathrm{Tm}}_{2}{\mathrm{Fe}}_{14}\mathrm{B}$ single crystals, we draw some general conclusions about ${R}_{2}{\mathrm{Fe}}_{14}\mathrm{B}$ alloys. The overall behavior of the resistivity is determined mainly by Fe atoms; however, contributions from rare-earth atoms are clearly observed at low temperatures. Large variations of the Hall resistivity are found near the spin reorientation and Curie temperatures. They can be attributed to critical magnetization fluctuations which enhance skew scattering in these regions. We calculate spin fluctuations making use of a phenomenological molecular-field model for an anisotropic ferromagnet. Our calculations account quite well for the observed anomalies in the spontaneous Hall coefficient. Away from the critical regions, side-jump scattering of charge carriers seems to be responsible for the Hall effect.
Highlights
Transport properties of magnetic materials have been the subject of rather intensive research, both experimental and theoretical, for the last few decades
In this paper we report the results of electrical resistivity and Hall effect measurements in R2Fe14B
As the temperature increases, is observed to rise rapidly up to T Ϸ0.5Tc. This rise is faster than the T5/3 that is predicted by spin fluctuations theory.[6]
Summary
Transport properties of magnetic materials have been the subject of rather intensive research, both experimental and theoretical, for the last few decades. Variations of the electrical resistivity with temperature and magnetic field provide relevant information about how itinerant magnetic electrons are.[6] On the other hand, asymmetric current carrier scattering which is subject to spin-orbit interactions gives rise to a magnetization-dependent Hall effect.[7] Its magnitude has been shown to be proportional to the third moment of the deviation of the magnetization from its mean value.[8,9] large variations of the anomalous Hall coefficient can be expected near critical points These should be quite different through first-order transitions where spin fluctuations remain within bounds. In this paper we report the results of electrical resistivity and Hall effect measurements in R2Fe14B
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
