Soft Magnetic Materials

Abstract

AbstractThis article provides a summary of the basic properties and the essential phenomenology of application‐oriented soft magnetic materials. Starting from an introductory section, where the magnetization process and the involved energetic aspects are highlighted, the physical rationale for the soft magnetic behavior of the materials is discussed, and a comparative illustration of their main physical, mechanical, and magnetic parameters is provided, the materials are classified according to their composition. We start from pure iron, the historical benchmark for any magnetic material, and pass through the selected alloys and compounds displaying the right combination of properties, including abundance of raw elements and costs, making them attractive for applications. We thus illustrate preparation methods, physical and magnetic properties, and applicative attributes of the following materials: (i) pure iron and low‐carbon steels; (ii) nonoriented and grain‐oriented Fe–Si alloys; (iii) High‐Si, Fe–Al, and Fe–Al–Si alloys; (iv) soft magnetic composites; (v) amorphous alloys; (vi) nanocrystalline alloys; (vii) Ni–Fe and Co–Fe alloys; (viii) soft ferrites. For each material, we summarize (i) compositional features and intrinsic physical and magnetic properties; (ii) metallurgical aspects and preparation techniques; (iii) magnetization process and magnetic hysteresis; (iv) energy losses and their dependence on the magnetizing frequency; (v) dependence of the magnetic properties on temperature and stress; (vi) mechanical properties; (vii) applications.