Competition effect of light and heavy rare earth in Pr1-Gd Co3 compounds with large coercivity and exchange bias

The effect of Gd doping on the structure and magnetic properties of PrCo3 compound was systematically studied, and a large zero-field cooling exchange bias effect at room temperature was observed. The results show that Pr1-xGdxCo3 (x = 0.0–1.0) series ribbons samples retains the rhombohedral structure of PuNi3 type. The addition of Gd element linearly reduce the lattice constant. Large coercivity strengthening and zero-field cooling exchange bias effect were stable below Curie temperature. At 10 K, the abnormal minimum saturation magnetization MS occurs at the critical point xc = 0.6, which corresponds to the maximum critical field, and the pinning effect is the strongest. At the same time, the maximum critical field is accompanied by the strongest exchange bias field, up to 14.92 kOe, showing a large unidirectional anisotropy. The coercivity HC is also improved by pinning effect, reaching a maximum of 23.17 kOe at the critical point xh = 0.5. Due to the influence of HEB, the actual coercivity HC1 was as high as 36.23 kOe. The mechanism of these phenomena was explained specifically in this paper. This work provides a novel idea for the development of permanent magnet materials and exchange bias materials.