Dynamic magnetoelectric response of composite multiferroics cylinders

Abstract

The effect of several mechanical boundary conditions on the dynamic magnetoelectric (ME) effect is analytically investigated for layered cylindrical composites. The study consists of deriving a mechanics-based model for two concentric cylinders made of lead-zirconate-titanate (PZT) and cobalt ferrite (CoFe 2 O 4 ), separated by a thin elastic layer, which is treated as strain mediator with no effect on the functional behavior of the system. Different thicknesses of the cylindrical composites and the elastic layer are considered in this study. For each case, nine sets of boundary conditions, four traditional and five non-traditional, were applied. Results show the dependence of the ME effect on the boundary conditions as well as on the inclusion of the elastic layer between the two cylinders, where both affect the strain transduction between the active layers; namely the piezomagnetic (CoFe 2 O 4 ) and piezoelectric (PZT) layers. It was found that the maximum ME effect is attained for conditions in which the outer boundary is subjected to a uniform mechanical pressure. The inclusion of a thin elastic bonding layer was found to increase the ME response, the thickness of which was further investigated to establish limits of applicability of the reported model.

Noncontact spatiotemporal strain mapping of composite multiferroic cylinders

“…Analytical models predict the concentric cylinder geometry to exhibit a giant magnetoelectric response due to the curvature enhancing the strain transfer between material layers (Wang et al 2010a). Our group has extensively studied the CME response of the concentric cylinder structure using experimental, analytical, and computational analyses (Newacheck et al 2018;Chavez et al 2016;Youssef et al 2020a). Specifically, we have experimentally investigated the effect of the bias magnetic field direction, electric field direction, and bonding methods, while analytically explored the effect of mechanical boundary conditions, and developed validated computational models (Newacheck et al 2018;Chavez et al 2016;Youssef et al 2020a, b).…”

Long-Term Converse Magnetoelectric Response of Actuated 1-3 Multiferroic Composite Structures

“…The sample was continuously loaded, electrically and magnetically, over 45 days with a DC magnetic field of 500 Oe and a simultaneous AC electric field of 20 kV/m at a frequency of 32.5 kHz to study the long-term performance of the multiferroic cylinder composite structure. These conditions were selected based on a priori experimental studies [12][13][14][17][18][19][20][27][28][29]. The sample was held in place using a 3D-printed mount that was centered perpendicularly between the two poles of an electromagnet.…”

Demagnetization Effect on the Magnetoelectric Response of Composite Multiferroic Cylinders

“…This is due to the practical challenges of experimentally replicating this situation, i.e., constructing a magnetic field source with a radially emanating magnetic field, hence the persistent focus on analytically investigating this boundary-value problem within the realm of continuum mechanics. It is, however, important to note that previous experimental investigations of concentric ring structures have demonstrated the multidirectional emanation of magnetic flux when operating the composite ring under the converse magnetoelectric coupling paradigm [30,[44][45][46]. This configuration can then be used to generate and apply an AC magnetic field.…”

“…Starting with the pioneer analytical work of Wang et al using the effective medium theory, to the recent reports by Youssef et al, these analytical models focus on mechanistically describing the dynamic magnetoelectric response of concentric cylinders [30,[37][38][39][40]46]. Wang et al assumed directly and perfectly bonded piezoelectric and magnetostrictive cylinders, and investigated the effect of four mechanical boundary conditions on the overall direct magnetoelectric response [37][38][39][40].…”

“…Wang et al assumed directly and perfectly bonded piezoelectric and magnetostrictive cylinders, and investigated the effect of four mechanical boundary conditions on the overall direct magnetoelectric response [37][38][39][40]. Youssef et al recently published a subsequent analytical investigation to supplement Wang's model by considering an expanded set of mechanical boundary conditions [30,46]. They also accounted for the inclusion of an elastic bonding layer; the systematic investigation of the strain distribution, given as the prime mediator between the applied magnetic field and the resulting change in polarization; and the exploration of the failure due to the generated mechanical stresses in all constituents [30,46].…”