page_title: Ferrimagnetism
section_title: Effects of temperature
hierarchical_section_title: Ferrimagnetism / Effects of temperature
context_page_description: In physics, a ferrimagnetic material is one that has populations of atoms with opposing magnetic moments, as in antiferromagnetism; however, in ferrimagnetic materials, the opposing moments are unequal and a spontaneous magnetization remains. This happens when the populations consist of different materials or ions.
  Ferrimagnetism is exhibited by ferrites and magnetic garnets. The oldest known magnetic substance, magnetite, is a ferrimagnet; it was originally classified as a ferromagnet before Néel's discovery of ferrimagnetism and antiferromagnetism in 1948.
  Known ferrimagnetic materials include yttrium iron garnet; cubic ferrites composed of iron oxides with other element such as aluminum, cobalt, nickel, manganese, and zinc; and hexagonal ferrites such as PbFe₁₂O₁₉ and BaFe₁₂O₁₉ and pyrrhotite, Fe1−xS.
context_section_description: Ferrimagnetic materials are like ferromagnets in that they hold a spontaneous magnetization below the Curie temperature and show no magnetic order (are paramagnetic) above this temperature. However, there is sometimes a temperature below the Curie temperature, at which the two opposing moments are equal, resulting in a net magnetic moment of zero; this is called the magnetization compensation point. This compensation point is observed easily in garnets and rare-earth–transition-metal alloys (RE-TM). Furthermore, ferrimagnets may also have an angular-momentum compensation point, at which the net angular momentum vanishes. This compensation point is a crucial point for achieving high speed magnetization reversal in magnetic memory devices.
caption: ➀ Below the magnetization compensation point, ferrimagnetic material is magnetic. ➁ At the compensation point, the magnetic components cancel each other and the total magnetic moment is zero. ➂ Above the Curie temperature, the material loses magnetism.