Orthoferrite

Orthoferrites have an orthorhombic crystal structure with a space group Pbnm and most are weakly ferromagnetic.

Its presence leads to a small canting of the sublattices, making the orthoferrites “weak” ferromagnets with

Another interesting feature of these materials is the fact that some of them exhibit a transition as a function of temperature, in which the direction of the antiferromagnetically ordered spins and consequently also of the net magnetization rotates by 90°.

[2] The combination of high magnetic resonance frequencies with very large magnetooptical effects makes the orthoferrites interesting objects for study of laser-induced dynamics.

Orthoferrites are transparent, and can modify the polarisation of a beam of light under the control of a magnetic field (Faraday rotation).