Dresden 2014 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 52: Magnetic Materials IV

MA 52.5: Vortrag

Freitag, 4. April 2014, 10:30–10:45, HSZ 403

High-throughput search for new rare-earth lean permanent magnets — •Dagmar Goll, Ralf Löffler, Johannes Herbst, Roman Karimi, and Gerhard Schneider — Hochschule Aalen, Institut für Materialforschung, Beethovenstraße 1, 73430 Aalen

Fe-Nd-B magnets with their extremely high performance have severe disadvantages in cost-efficiency due to their rare earth (RE) content and lifetime at T > 200^∘C. The demand for novel hard magnetic phases with better available RE metals, reduced RE content or RE free therefore is tremendous. The chances for the existence of such materials still exist due to the large number of so far unexplored alloy systems. To scan quickly through higher component systems we have developed suitable high-throughput approaches which are based on heterogeneous non-equilibrium states, so that one sample may be sufficient to cover the most relevant part of a phase diagram [1]. The efficiency of the high-throughput method is first demonstrated for the well-known systems Co-Sm and Fe-Nd-B. To identify the magnetic phases and analyze their intrinsic material parameters (anisotropy constant K₁, saturation polarization J_s, Curie temperature T_C) a combination of optical microscopy, Kerr microscopy and energy dispersive X-ray analysis in a scanning electron microscope is used. This allows to estimate K₁ and J_s from domain size and domain contrast. The high-throughput method is second demonstrated for discovered new hard magnetic phases based on Fe-Ce-X (X: additive) to estimate their potential concerning industrial relevance (supported by BMBF). [1] D. Goll, R. Löffler, J. Herbst, R. Karimi, G. Schneider, J. Phys.: Cond. Matter 26 (2014) in press.