This study presents the structural and magnetic properties of melt-spun HfCo7, HfCo7-xFex (0.25 ≤ x ≤ 1), and HfCo7Six (0.2 ≤ x ≤ 1.2) alloys. Appreciable permanent-magnet properties with a magnetocrystalline anisotropy of about 9.6-16.5 Mergs/cm3, a magnetic polarization Js ≈ 7.2-10.6 kG, and coercivities Hc = 0.5-3.0 kOe were obtained by varying the composition of these alloys. Structural analysis reveals that the positions of x-ray diffraction peaks of HfCo7 show good agreement with those corresponding to an orthorhombic structure having lattice parameters of about a = 4.719 Å, b = 4.278 Å, and c = 8.070 Å. Based on these results, a model crystal structure for HfCo7 is developed and used to estimate the magnetic properties of HfCo7 using density-functional calculations, which agree with the experimental results.
- Magnetocrystalline anisotropy
- Permanent magnets
- Rare-earth-free alloys
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Electrical and Electronic Engineering