Elements that display ferromagnetic properties, the strongest type of magnetic property, in their elemental state include iron, cobalt, nickel, gold and dysprosium. Other elements display ferromagnetic properties as part of a compound, such as manganese and chlorine.
The ferromagnetism of an element is dependent upon its temperature. As temperatures increase, the kinetic energy of the atoms increases to a point where the element loses its ferromagnetism. This temperature is known as the Curie temperature, and is different for each element. It is expressed using the Kelvin scale.
For example, the Curie temperature for iron is 1,043 K, 1,388 K for cobalt, 627 K for nickel, 292 K for gold and 88 K for dysprosium. Because it loses its ferromagnetism at such a low temperature, equivalent to minus 301.2 F, dysprosium is unlikely to act as a ferromagnet in the natural environment.
Common ferromagnetic compounds include chromium(IV) oxide, manganese(III) bismuthide, europium oxide, yttrium ferrite and cobalt(II) chloride. As with the single elements, the ferromagnetic activity of these compounds varies based on the Curie temperature, or a similar measurement called the Néel temperature. The amount of ferromagnetic activity displayed by an element or compound can also be expressed through its magnetic moment measurement.