Design and characterization of magneto-electric sensors. What are the limits?

Multi-functional materials can respond to more than one external stimulus. Here we will present a magneto-electric system, which couples two switchable states; polarization and magnetisation. In magneto-electric materials, magnetic domains can be tuned by the application of an external electric field and electric domains are switched by a magnetic field via a magneto-electric coupling (ME) across the oxide interface. This two-order coupling can be effectively utilized in the development of multiple state memory elements, tuneable magneto-electric inductors where the electric field tunes the permeability in a voltage variable self-inductance device or as magnetic sensors where the magnetic field produces an electric signal. In the case of magnetic field sensors, their sensitivity, room temperature operation and zero power consumption are particularly attractive. In the area of power electronics such materials show potential as high-quality variable inductors, where miniaturisation of the inductors could enable small, lightweight products.