Only certain materials, such as iron, feel a magnetic force. Permanent magnets can come in lots of different shapes and sizes. Bar magnets and horseshoe magnets are two of the most common shapes ...

meaning they act like little magnets. In atoms with filled electron shells, these magnetic moments cancel each other out because each pair of electrons have moments that point in opposite directions.

These new iron-nitride magnets are stronger ... but they’re highly dispersed, meaning that large volumes of material must be ...