Structure and intrinsic magnetic properties of Sm1−x Pr x Co5 (x = 0–0.6) compounds

Abstract

In this work, the effects of Pr content on the structure and intrinsic magnetic properties of Sm1−x Pr x Co5 (x = 0–0.6) compounds prepared by induction melting were systematically investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), and magnetic measurements. Microstructural observation and chemical composition analysis show that Sm1−x Pr x Co5 compounds are composed of (Sm, Pr)Co (1:5) phase and (Sm, Pr)-rich grain boundary phase. XRD results show that all the Sm1−x Pr x Co5 compounds have a (Sm, Pr)1Co5 main phase with the hexagonal CaCu5-type crystal structure and the (Sm, Pr)2 Co7 impurity phase. In addition, the detailed research shows that the lattice constants (a, c) and unit volume (V) are all enlarged with the increases in Pr content. According to the magnetic measurements, as the Pr content increases to larger than 0.4, both the Curie temperature (T C) and the anisotropy field (H A) of all the Pr-doped compounds decrease rapidly. Meanwhile, the magnetization of Sm1−x Pr x Co5 compounds at applied field of 14 T (M 14 T) are observably improved with Pr doping content of x > 0.3. Among them, Sm0.6Pr0.4Co5 compound exhibits slightly lower H A and T C, but much higher M 14 T than those of the binary SmCo5, indicating that doping of proper Pr content into SmCo5 compound can optimize the intrinsic magnetic properties. As a result, the optimal intrinsic magnetic properties of H A = 29.11 T, T C = 989 K, and M 14 T = 102.31 mA·m2·g−1 are obtained in Sm0.6Pr0.4Co5 compound. The effects of Pr content on chemical composition, cell parameter, morphology, and magnetic properties of Sm1−x Pr x Co5 (x = 0–0.6) compounds were systematically investigated. The anisotropy field, H A, of Sm1−x Pr x Co5 compounds is depended on Pr content. Optimal intrinsic magnetic properties of H A of 29.11 T, T C of 989 K, and M14 T of 102.31 mA·m2·g−1 are obtained in Sm0.6Pr0.4Co5 compound.