Influence of shape demagnetizing effect on piezomagnetic coefficient in magnetostrictive/piezoelectric laminate composite

The piezomagnetic coefficients of different lengths FeNi-FACE plates are tested as a function of magnetic bias field. Taking the shape demagnetizing effect into account, the changing magnetic field (H_ch) in the definition of piezomagnetic coefficient (d₃₃) is taken as applied AC magnetic field (H_ac) and effective AC magnetic field (H_aceff), respectively. When H_ch is regarded as H_ac, the maximum d₃₃ of different lengths FeNi-FACE plates are increasing with the increase of the rectangular plate´s length. When H_ch is taken as H_aceff, the maximum d₃₃ of different lengths FeNi-FACE plates are roughly equal, and this result is matching with the theoretical analysis of an analytical model of piezomagnetic coefficient based on the nonlinear constitutive relations of magnetosrictive materials. In order to convert the d₃₃ under the two situations, the concept of a matching factor is proposed. In actually application, the d₃₃ of different shape magnetostrictive materials can be accurately determined by the matching factor.