FePt Hard Magnets

TLDR

FePt alloys are prized for their superior magnetic, chemical, and mechanical properties, making them attractive for permanent magnets, MEMS, and high‑density storage applications. The paper investigates phase formation and magnetic characteristics of L10‑structured FePt‑based materials. The study examines both thin‑film and bulk routes, detailing the creation of bulk nanocrystalline Fe100‑xPtx powders via mechanical alloying followed by annealing. This approach yields a variety of non‑equilibrium phase combinations.

Abstract

Abstract The FePt alloys have recently attracted considerable attention due to their excellent intrinsic magnetic, chemical and mechanical properties. Their possible usage ranges from permanent magnets for special applications (e.g. in micro‐electro‐mechanical systems, magnetic MEMS, and in aggressive environments) to ultra‐high density magnetic storage media. The article describes general aspects concerning the phase formation and magnetic properties of materials based on the L 1 0 FePt phase. Both thin film and bulk approaches are considered. The production of bulk nanocrystalline Fe 100‐x Pt x powders by mechanical alloying and subsequent annealing is described. Various combinations of phases, away from thermodynamic equilibrium, have been obtained using this technique.