Magnetoelectrical

Magnetoelectrical, or magnetoelectric, refers to effects and materials in which magnetic and electric properties are coupled so that magnetic fields can influence electric polarization and electric fields can influence magnetization. In the linear magnetoelectric effect, polarization responds proportionally to an applied magnetic field and magnetization responds proportionally to an applied electric field. This coupling is described by the magnetoelectric tensor α_ij, which encodes how different components of magnetic and electric fields interact within a material.

The effect typically arises in materials that break both inversion symmetry and time-reversal symmetry, such as certain antiferromagnets and multiferroics. The phenomenon was theoretically anticipated in the mid-20th century and the first experimental observation occurred in chromium oxide (Cr2O3) in 1959. Since then, various magnetoelectric materials have been studied, including Cr2O3 as a classic example and complex oxides known for coexisting magnetic and electric order, such as BiFeO3 and certain Mn-based compounds. Researchers also explore engineered structures, like magnetoelectric laminates that combine magnetic and piezoelectric or ferroelectric layers to enhance coupling.

Applications of magnetoelectric coupling are largely in the research and development phase. They hold potential for low-power spintronic devices, electrically controlled magnetic memory, and sensitive field sensors. A key area of work is discovering materials with larger magnetoelectric effects at room temperature and integrating such coupling into practical devices while mitigating losses and fabrication challenges.