Structural, magnetism and magnetocaloric effects of GdxEr1-xNi compounds

RNi (R=rare earth) compounds have been considered as one of the most promising candidates for magnetic refrigeration applications. In this work, the crystal structure, magnetism and magnetocaloric effects of the pseudo-binary rare earth intermetallic compounds Gd _xEr _1-xNi (x = 0, 0.25, 0.5, 0.75 and 1) were investigated. The results show that, with the increase of Gd content, the crystal structure transforms from orthorhombic FeB-type structure (space group Pnma, no. 62) for ErNi and Gd _0.25Er _0.75Ni to monoclinic crystal structure (space group P21/m, no. 11) for Gd _0.5Er _0.5Ni and orthorhombic CrB-type structure (space group Cmcm, no. 63) for Gd _0.75Er _0.25Ni and GdNi. Furthermore, the Curie temperatures (T _C) of the Gd _xEr _1-xNi compounds increase from 11.04 K to 74.00 K with increasing Gd content, and a linear relationship is found: y = 61.608x + 11.404. All compounds undergo a second-order phase transition (SOPT) from ferromagnetic (FM) to paramagnetic (PM), and a Large MCE is observed close to the T _C. Gd _xEr _1-xNi compounds have comparable or even better properties than some of the magnetic refrigeration materials reported in the literature, and can be candidates for medium- and low-temperature magnetic refrigeration materials. This study sheds light on tuning the T _C within a specific temperature region and MCE of (Gd, Er)Ni compounds via adjusting the molar ratio of Gd and Er.