Magnetic interactions and weak ferromagnetism in the rare-earth orthochromites

The magnetic properties of the rare-earth orthochromites have been intensively studied by neutron diffraction and inelastic scattering, bulk magnetization, optical absorption spectroscopy, specific heat, acoustic velocity, and resonance measurements. These materials process a variety of different magnetic structures, and several undergo spontaneous spin reorientation phase transitions. The properties of these compounds are reviewed with emphasis on the key role played by the coupling between the chromium and rare spin systems.