Effect of light and heavy rare earth mixing on the properties of Nd1−xGdxCo2

Abstract

We report here on the resistivity (ρ) and heat capacity (Cp) on Nd1−xGdxCo2 (with 0 ⩽ x ⩽ 1) down to 2 K and up to 14 T. Distinct changes were observed in all measured properties across the paramagnetic to ferromagnetic transition along with the cubic to tetragonal transition (Tc = 100 K for x = 0 and Tc = 400 K for x = 1), and across the spin reorientation transition along with the tetragonal to orthorhombic transition (Tsr = 42 K x = 1, and Tsr = 70 K for x = 0.8). Both the transitions are associated with a significant change in entropy due to the coupling of the magnetic and structural transitions. The external magnetic field causes both the transitions to occur at higher temperatures, leading to large magneto caloric as well as large magneto resistance effects. Hence, Gd substitution in the site of Nd hints at the functionality of these doped materials near room temperature. However, near a concentration of 0.4 ⩽ x ⩽ 0.5, an anomalous behavior of the tetragonal to orthorhombic transition for the externally applied magnetic field is observed.