Unlike nucleation-controlled Nd-Fe-B-based permanent magnets, the Sm 2Co 17-type maintains its excellent magnetic properties at elevated temperatures 15. Sm 2(Co,Fe,Cu,Zr) 17 is an important industrially used material system, since it has both a high Curie temperature and a high magnetocrystalline anisotropy 10, 11, 12, 13, 14.
These include microwave tubes, gyroscopes and accelerometers, reaction and momentum wheels to control and stabilize satellites, magnetic bearings, sensors and actuators. Pinning-controlled permanent magnets operating at elevated temperatures boost device performances of magnet-based industrial applications 1, 2, 3, 4, 5, 6, 7, 8, 9. With further development, this knowledge can be applied to produce samarium cobalt permanent magnets with improved magnetic performance. Using ultra-high-resolution experimental and theoretical methods, we revealed the atomic structure of the single phases present and established a direct correlation to the macroscopic magnetic properties.
The iron content controls the formation of a diamond-shaped cellular structure that dominates the density and strength of the domain wall pinning sites and thus the coercivity. Here we present model magnets with an increased iron content based on a unique nanostructure and -chemical modification route using Fe, Cu, and Zr as dopants.
These are of importance for high-temperature industrial applications due to their intrinsic corrosion resistance and temperature stability. A higher saturation magnetization obtained by an increased iron content is essential for yielding larger energy products in rare-earth Sm 2Co 17-type pinning-controlled permanent magnets.
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