Description
Multiferroic materials have seen an explosion of research interest in recent years due to their usefulness in application areas including sensing, actuation, and communication. Strain mediated multiferroic composites imply broad improvements in terms of electronic device power consumption, wireless power transfer, and high-performance sensing due to their coupling of the magnetic and electric paradigms by way of strain transfer across their interface. These strain-mediated composites address many of the weaknesses of single-phase, monolithic magnetoelectric materials such as near-inoperability at room temperature and similarly exhibit enhanced coupling coefficients in comparison. In conjunction with the use of a concentric ring structure, experimentally shown to further increase the coupling as opposed to other composite structures, significant research attention has been afforded these composites. These include numerous computational modeling efforts, including analytical and finite element modeling studies. Additionally, numerous experimental studies have examined the converse magnetoelectric coefficient characterization, strain distribution behavior, and the effect of multidirectional magnetic fields and polarization direction. However, fundamental gaps exist across these past analyses in both areas. In terms of computational studies, no comprehensive effort has been made to create a fully-coupled Multiphysics simulation including all electrical and magnetic effects or boundary conditions. Through the creation of such a finite element model, complicated effects such as onion state magnetization and shape anisotropy were observed. Magnetoelectric and principal strain response behaviors of this model are verified by extensive comparison with past experimental studies and found to be in good agreement. Keeping with the limitations in past computational analyses, no experimental studies have studied on the effect of long-term loading on multiferroic concentric ring composites, an important metric for application adoption. The extended fatigue characterization of these composite structures resulted in a significant degradation in terms of interface quality and magnetoelectric response. Overall, valuable utilities and conclusions can be drawn from both studies performed herein to advance strain mediated multiferroic technology.
