Effect of Ni substitution on the magnetic and electrical properties of Dy0.73Tb0.27Fe2

Abstract

Alloys of Dy0.73Tb0.27Fe2−xNix [0≤x≤2] were prepared and the lattice parameters obtained at room temperature showed a deviation from Vegard’s law owing to the presence of magnetovolume effect. Magnetization studies were carried out up to an applied field of 10 kOe in the temperature range 4.2–750 K. Magnetization data at 4.2 K indicate the effect of domain wall pinning. Temperature dependence of magnetization curves showed maxima at low temperatures as a consequence of this pinning effect. Electrical resistivity studies were carried out in the temperature range 16–750 K. A minimum observed for x=2 in the vicinity of its Curie temperature is attributed to the presence of critical fluctuations due to short-range spin ordering of the rare earths. All the samples, except x=2, showed a T2 dependence at low temperatures and this has been attributed to electron-spin wave scattering mechanism.