Magnetoelectric effect material

特許 権利維持 The magnetoelectric (ME) effect is the phenomenon of inducing magnetic (electric) polarization by applying an external electric (magnetic) field. The effects can be linear or/and non-linear with respect to the external fields. In general, this effect depends on temperature. The effect can be expressed in the following form P_i=\sum \alpha_{ij}H_j + \sum \beta_{ijk}H_jH_k+\ldots M_i=\sum \alpha_{ij}E_j + \sum \beta_{ijk}E_jE_k+\ldots where P is the electric polarization, M the magnetization, E and H the electric and magnetic field, and α and β are the linear and nonlinear ME susceptibilities. The effect can be observed in single phase and composite materials. Some examples of single phase magnetoelectrics are Cr2O3,[1] and multiferroics materials which show a coupling between the magnetic and electric order parameters. Composite magnetoelectrics are combinations of magnetostrictive and electrostrictive materials, such as ferromagnetic and piezoelectric materials.