Suppression of creep-regime dynamics in epitaxial ferroelectric BiFeO3 films

Abstract

Switching dynamics of ferroelectric materials are governed by the response of domain walls to applied electric field. In epitaxial ferroelectric films, thermally-activated ‘creep’ motion plays a significant role in domain wall dynamics, and accordingly, detailed understanding of the system’s switching properties requires that this creep motion be taken into account. Despite this importance, few studies have investigated creep motion in ferroelectric films under ac-driven force. Here, we explore ac hysteretic dynamics in epitaxial BiFeO3 thin films, through ferroelectric hysteresis measurements, and stroboscopic piezoresponse force microscopy. We reveal that identically-fabricated BiFeO3 films on SrRuO3 or La0.67Sr0.33MnO3 bottom electrodes exhibit markedly different switching behaviour, with BiFeO3/SrRuO3 presenting essentially creep-free dynamics. This unprecedented result arises from the distinctive spatial inhomogeneities of the internal fields, these being influenced by the bottom electrode’s surface morphology. Our findings further highlight the importance of controlling interface and defect characteristics, to engineer ferroelectric devices with optimised performance.

Large Piezoelectricity and Ferroelectricity in Mn‐Doped (Bi0.5Na0.5)TiO3‐BaTiO3 Thin Film Prepared by Pulsed Laser Deposition

“…It is also found the hysteresis behavior is frequency dependent, that is, a decrease in the slope d P/ d E and an increase in the coercive field E c occur when measuring frequency increases. The similar phenomenon, which can be attributed to the domain wall dynamics, was also observed in many other ferroelectric thin films . It is known that the variation in frequency determines the relative time duration that ferroelectric materials stay in each domain wall dynamic regime (i.e., relaxation, creep or flow region).…”

Strain and orientation engineering in ABO3 perovskite oxide thin films

“…Using substrate miscuts has been very important in this regard, as this technique can force the films to grow with preferred structural and ferroelastic domains (cf figure 5(b)). This is important as domain switching and fatigue are heavily underpinned by domain structure [74][75][76].…”

“…This composition gives large MR effects near room temperature [129], attractive for integration into spin valves [130]. Finally, LSMO is an important addition to any oxide thin film laboratory as a high quality electrode material for oxide heterostructures, including ferroelectrics [75,131].…”

Large-scale Monte Carlo simulations for the depinning transition in Ising-type lattice models

“…Between them, there exists a secondorder dynamical phase transition, called as the "depinning transition" [1,2,3,4,5,6,7,8]. For several decades, the depinining transition has been the focus of the experimental and theoretical research, which are common to a wide variety of phenomena, including the liquid invasion in porous media [9], the contact line in wetting [10], the vortices in type-II superconductors [11,12], the charge-density waves [13], the fracture propagation [14,15], the dislocation dynamics in crystal plasticity [16], and the domain-wall motions in ferromagnetic and ferroelectric materials [17,18,19,20]. Practically, understanding the fundamental mechanism of the depinning transition plays an important role in predicting and controlling the motions of the magnetic domain walls in nanomaterials [21,22,23], thin films [8,24], and semiconductors [20,25], which is key to the realization of the new classes of potential nonvolatile storage-class devices [26,27].…”