Towards Production of Cost-Effective Modification of SmCo5-Type Alloys Suitable for Permanent Magnets

Abstract

SmCo5 constitutes one of the strongest classes of permanent magnets, which exhibit magnetocrystalline anisotropy with uniaxial character and enormous energy and possess high Curie temperature. However, the performance of SmCo5 permanent magnets is hindered by a limited energy product and relatively high supply risk. Sm is a moderately expensive element within the lanthanide group, while Co is a more expensive material than Fe, making SmCo5-based permanent magnets among the most expensive materials in the group. Subsequently, the need for new materials with less content in critical and thus expensive resources is obvious. A promising path of producing new compounds that meet these requirements is the chemical modification of established materials used in PM towards the reduction of expensive resources, for example, reducing Co content with transition metals (like Fe, Ni) or using as substitutes raw rare earth materials with greater abundance than global demand, like Ce and La. Important instruments to achieve these goals are theoretical calculations, such as ab initio methods and especially DFT-based calculations, in predicting possible stable RE-TM intermetallic compounds and their magnetic properties. This review aims to present the progress of recent years in the production of improved SmCo5-type magnets.

The Success of Fabrication of Pure SmFe2 Phase Film with Outstanding Perpendicular Magnetic Anisotropy

“…SmCo 5 exhibits high coercivity and saturation magnetization, with coercivity reaching 15-35 kOe and a maximum energy product of 18-20 MGOe [17]. It also possesses a certain degree of temperature resistance [18]. However, its cost is higher due to the use of the rare element cobalt.…”

Phase Formation and Magnetic Properties of (Y1−xSmx)Co5 Melt-Spun Ribbons

“…This interplay of electronic configurations contributes significantly to the magnetocrystalline anisotropy observed in these materials. Considering Y as a high-abundance rare-earth element, it is believed that adding the element Y is a promising and cost-effective way to enhance the magnetic properties of 1:5-type permanent magnets [21][22][23].…”