Multiferroics are insulating materials that are simultaneously magnetically ordered and ferroelectric. From a fundamental standpoint it is interesting to understand the properties and coupling of these two disparate types of order. These materials could also be useful for a variety of applications such as for spintronics, sensors, and multifunctional memory. Type-I multiferroics are characterized by robust ferroelectric order that develops at high temperatures and usually a separate magnetic sublattice which orders at lower temperature. There is often weak coupling between the two order parameters. For type-II multiferroics, the magnetic order develops first and permits a very weak ferroelectric order to develop. Typically, the transition temperatures are low, but the magnetoelectric coupling is strong. Neutron scattering plays an essential role in elucidating all aspects of this class of materials, crystal structure and ferroelectric order, magnetic structure, and the dynamics and energetics associated with both types of order.
Neutron Scattering - Magnetic and Quantum Phenomena