Introduction to magnetism and new permanent magnets with reduced use of rare-earth element

ALEX AUBERT HERNÁNDEZ

(BCMATERIALS)

Introduction to magnetism and new permanent magnets with reduced use of rare-earth element

Magnetism and magnetic materials are the core of investigation in many fields as they can be used in a wide range of applications, from medicine to intelligent devices. Every material have magnetic properties but only some of them exhibit a spontaneous magnetic ordering. When this ordering is strong enough, it leads to the so-called permanent magnets, which are used today in wind turbines, hybrid-electric vehicles, robotics, automation etc. The most powerful permanent magnets are based on intermetallic compounds containing rare-earths elements, such as Nd, Sm, Dy, or Tb. However, due to recent supply chain vulnerability and price volatility of these elements - leading to the 2010/2011 Rare Earth Crisis - there is a continuing risk of a shortage of rare-earth metals, especially valid for Dy and Tb. As a consequence, researchers nowadays focus on the development of novel hard magnetic materials with a reduced critical rare-earth content.   The talk will be divided in two sections: 1) A general introduction to magnetism, hysteresis and magnetic characterization; 2) An introduction to permanent magnets with reduced use of rare-earth element based on the ThMn-12 structure.