How defects make permanent magnets even more efficient‎

Rare-earth magnets are essential for electric motors in vehicles, drones, and trains, forming the backbone of modern, environmentally friendly mobility. These are not simple blocks of metal, but carefully engineered materials with a complex internal nanostructure composed of tiny building blocks called phases, each with its own crystal structure, chemistry, and physical properties. How magnetization behaves at the interfaces between these tiny building blocks and how well it resists demagnetizing forces ultimately determines the strength and stability of the magnet, and therefore the efficiency and reliability of the motor or generator.