Intrinsic and extrinsic magnetic properties of nanocrystalline Pr2(Co, Fe)7. Issue 4 (22nd January 2014) - Fersi, R.
Abstract In this work, we present a study focused on the effect of partial substitution of Co by Fe on structure and magnetic properties of nanocrystalline Pr2Co7. These compounds were synthesized by mechanical alloying and to correlate their properties with microstructural evolution, a multi‐scale study by: X‐ray diffraction (XRD), transmission electron microscopy, and magnetization was carried out. The Rietveld analysis of XRD diagrams shows that Pr2Co7−xFex, annealed at 973 K, mainly adopt a hexagonal Ce2Ni7 type structure with P63/mmc space group. These pseudo‐ternary compounds exhibit more interesting magnetic properties than the binary Pr2Co7 compounds. A systematic study of the intrinsic magnetic properties of these alloys shows that the substitution leads to enhancement of the Curie temperatures (TC) by 26% for a Fe content equal to 0.5. This increase is due to the electronic as well as the magnetovolume effects. In addition, the study of extrinsic magnetic properties of the Pr2Co6.5Fe0.5 compound has revealed the existence of a large coercive field Hc, and a high remanent magnetization Mr. Our results show that in these alloys, iron in solid solution has a strong effect on hardness and ordering temperature, which is particularly promising for permanent magnet applications.