SmCo5 is a well-established material in the permanent magnet industry, a sector which constantly gains market share due to increasing demand but also suffers from criticality of some raw materials. In this work we study the possibility of replacement of Sm with other, more abundant rare earth atoms like Ce-La. These raw materials are usually called “free” rare-earth minerals, appearing as a by-product during mining and processing of other raw materials. Samples with nominal stoichiometry Sm1−xMMxCo5 (x = 0.1–1.0) were prepared in bulk form with conventional metallurgy techniques and their basic structural and magnetic properties were examined. The materials retain the hexagonal CaCu5-type structure while minor fluctuations in unit cell parameters as observed with X-ray diffraction. Incorporation of Ce-La degrade intrinsic magnetic properties, Curie temperature drops from 920 K to 800 K across the series and mass magnetization from 98 Am2/kg to 60 Am2/kg; effects which trade off for the significantly reduced price. Atomistic simulations, implemented based on Density Functional Theory calculations are used in the case of the stoichiometry with x = 0.5 to calculate atomic magnetic moments and provide additional insight in the complex interactions that dominate the magnetic properties of the material.

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In the present work we present a preliminary experimental and ab-initio study of a series of compounds with nominal composition Sm1-xMMxCo5-y-zFeyNiz ( x = 0 – 0.7; y = 0.5 – 1.5; z = 0.5 – 1). Compounds with MM content up to 50% were successfully synthesized in CaCu5-type structure, retaining uniaxial magnetocrystalline anisotropy. Magnetization values are within the 85 to 50 Am2/kg range, with Ni content playing a significant role in stabilization of the structure at the cost of magnetization weakening. Theoretical calculations predict higher magnetization values, especially in the case of SmCo2.5Fe1.5Ni compound with a value close to that of SmCo5.

The use of the mischmetal alloy, comprised of La and Ce in 1:3 ratio, as a partial substitute for Sm in the CaCu5-type structure is explored, as a means for...

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