ferromagnetic

/ˌfɛroʊmæɡˈnɛtɪk/
adjective
  1. Having the property of being strongly attracted to a magnet and able to become magnetized permanently.
    • The ferromagnetic core in the transformer helps concentrate the magnetic field.
    • Iron, nickel, and cobalt are ferromagnetic metals.
    • Ferromagnetic materials are used to make permanent magnets.
Antonyms