Nonlinear Thermal-magneto-electric Equivalent Circuit for L-T Magnetoelectric Laminate

To describe the working process of magnetoelectric (ME) laminate with the equivalent circuit more accurately, the equivalent circuit model is optimized by introducing the temperature field and loss characteristics based on the nonlinear magnetostrictive constitutive relation, the complex modulus and the complex permittivity. Using the nonlinear magnetostrictive constitutive relation, the piezomagnetic coefficient and compliance coefficient of the piezomagnetic layer are calculated. Subsequently, the equivalent circuit is used to calculate the ME field coefficient, and the optimal thickness ratio of the laminate is also discussed. The effects of temperature, prestress and bias magnetic field on piezomagnetic coefficient, compliance coefficient and ME field coefficient are discussed in detail. The optimal bias magnetic field and the peak of ME field coefficient can be adjusted by changing prestress and temperature. Furthermore, the optimal thickness ratio can be obtained to reach the highest ME field coefficient.