physica status solidi (a) · 1993 · 95 citations · 24 references
Natural SciencesMaterials EngineeringMaterials ScienceCeramic MaterialsMagnetic MaterialsMetallurgyAlloysFerromagnetic MaterialsFerromagnetismMagnetization ProcessesMetalsPermanent MagnetsCompositionDomain NucleationFerromagnetic CeramicsMagnetic AlloysMetal MicrostructureMetallurgical Microstructure AnalysisMicrostructureTwin Boundaries
The alloys with composition around Sm11.5Co58.4Fe22.5Cu5.3Zr2.4 (at%) present hard magnet properties when their microstructure consists of a network of cells based on Sm2(Co, Fe)17, limited by boundaries based on Sm(Co, Cu)5 and cut by platelets based on (Sm, Zr)Co3. The genesis of this microstructure is studied by transmission electron microscopy of heat-treated specimens. The fractions and compositions of the phases formed are evaluated from atomic balance equations. The microstructure forms by nucleation growth of ordered R2:17 cells in the 1:7 matrix, then by nucleation of 1:3 platelets on the twin boundaries in R2:17. The processes are likely limited by diffusion.
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