Domain engineering in ferromagnetic morphotropic phase boundary with enhanced and non-hysteretic magnetostriction: A phase-field simulation

Giant and non-hysteretic magnetostriction is critical for magneto-mechanical applications, such as transducers, sensors, and actuators. In this work, the introduction of domain engineering into the single crystals near the ferromagnetic morphotropic phase boundary (MPB) is achieved through phase-field simulation, with the aim of exerting control over domain configuration and magnetostriction. It is found that intermediate external magnetic fields applied along non-easy magnetic axes during the nucleation stage can significantly affect the subsequent domain growth and evolution kinetics. The simulations reveal a domain wall broadening mechanism to explain the significantly improved non-hysteretic magnetoelastic responses observed in engineered tetragonal crystals. Our simulation results additionally demonstrate a discernible correlation between the domain wall densities and external fields in the engineered tetragonal domain. This research provides a potential pathway for the advancement of giant and non-hysteretic magnetostrictive material designs.