Electrically Driven Magnetic Domain Wall Rotation in Multiferroic Heterostructures to Manipulate Suspended On-Chip Magnetic Particles

Abstract

In this work, we experimentally demonstrate deterministic electrically driven, strain-mediated domain wall (DW) rotation in ferromagnetic Ni rings fabricated on piezoelectric [Pb(Mg1/3Nb2/3)O3]0.66-[PbTiO3]0.34 (PMN-PT) substrates. While simultaneously imaging the Ni rings with X-ray magnetic circular dichroism photoemission electron microscopy, an electric field is applied across the PMN-PT substrate that induces strain in the ring structures, driving DW rotation around the ring toward the dominant PMN-PT strain axis by the inverse magnetostriction effect. The DW rotation we observe is analytically predicted using a fully coupled micromagnetic/elastodynamic multiphysics simulation, which verifies that the experimental behavior is caused by the electrically generated strain in this multiferroic system. Finally, this DW rotation is used to capture and manipulate micrometer-scale magnetic beads in a fluidic environment to demonstrate a proof-of-concept energy-efficient pathway for multiferroic-based lab-on-a-chip applications.

Understanding and designing magnetoelectric heterostructures guided by computation: progresses, remaining questions, and perspectives

“…145 the motion of magnetic domain-walls with an electric field rather than a current. Electric-field-driven magnetic domain-wall motion has been demonstrated experimentally in a number of magnetoelectric heterostructures, [149][150][151][152] and computationally in a peculiar heterostructure consisting of a magnetic nanowire sandwiched by a Si bottom substrate and a Pb(Zr,Ti)O 3 (PZT) top film. 153 However, none of these reports have demonstrated an average magnetic domain-wall velocity exceeding 100 m/s, a speed comparable to that of current-driven magnetic domain-wall motion.…”

Enhanced magnetoelectric coupling in a composite multiferroic system via interposing a thin film polymer

“…5 15 For one of the specimens, adhesion promotor AP3000 and dielectric benzocyclobutene (BCB) monomer of 10 µm thick were spun onto the top electrode, followed by thermal curing in N 2 chamber at 250 o C. After poling the PMN-PT substrate, 5 nm Ti/15 nm Ni films were deposited by e-beam evaporation. The purpose of poling prior to the deposition of FM layer is to reorient spontaneous polarizations, thereby reducing the ferroelastic energy 16 and prepare the substrate to work in its linear piezoelectric regime.…”

“…In the specimen with interposed polymer, the electric-field-induced strain in the PMN-PT was first transferred to the polymer and then to the top FM Ni thin film, as opposed to the direct strain transfer usually found in a PMN-PT/Ni composite system. 5,15 To understand the difference in ME response between these two systems, in-plane magneto-optical Kerr (MOKE) magnetometry with in-situ electric fields was employed to study M-H hysteresis loop variation for both samples. The two MOKE specimens were oriented in three directions during the experiment such that the external magnetic field was applied in the direction at an angle θ of 0 o , 90 o and 45 o with respect to the [100] direction of PMN-PT (see Fig.…”

“…3,4 Among these, the use of electrical field to actuate strain-coupled multiferroic heterostructures has been widely demonstrated in the past few years as an energy-efficient pathway for controlling magnetization in the FM layer. [5][6][7] The Villari effect (a.k.a., magnetoelastic effect) describes the behavior where applied mechanical stress σ produces change in the magnetization in a material. 8 Optimizing the transfer of strain and magnetic response in strain-coupled multiferroic heterostructures is key to maximizing the Villari effect, which is at the core of applications such as magnetic random access memory (MRAM), field sensors, and actuators.…”

Controlling the stability of both the structure and velocity of domain walls in magnetic nanowires

“…Notwithstanding this, applications and device concepts for in-plane magnetized nanowires continue to develop for logic and sensing, 10,19,20 and a wide range of concepts for biotechnology and medicine applications, including magnetic tagging, detection of proteins and cells, as well as sorting and drug delivery. [21][22][23] These applications are driven to understanding and control DW behavior in nanowires with in-plane magnetization. For robust functional performance, DW behaviour needs to be highly repeatable in terms of both propagation and pinning; thus, variability in pinning behaviour or sensitivity of the propagation velocity to magnetic field will affect device reliability.…”