Its response lags behind a cycling applied field, a phenomenon known as hysteresis.  
When placed in an alternating environment, materials exhibiting this phenomenon lose energy according to Steinmetz's law.  Two important parameters characterizing materials that display this behavior are the coercivity and the remanence.  Bloch showed that the exchange energy associated with this phenomenon results in walls of finite thickness between Weiss domains.  Its response lags behind a cycling applied field, a phenomenon known as hysteresis.  FTP, name this property that is exhibited below the Curie point by cobalt, nickel, iron, and many permanent magnets.
When placed in an alternating environment, materials exhibiting this phenomenon lose energy according to Steinmetz's law.  
{ferromagnetism}