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Results for “ferroelastic switching”

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At least 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2019

Mechanical-force-induced non-local collective ferroelastic switching in epitaxial lead-titanate thin films

Ferroelastic switching in ferroelectric/multiferroic oxides plays a crucial role in determining their dielectric, piezoelectric, and magnetoelectric properties. In thin films of these materials, however, substrate clamping is generally thought to limit the electric-field- or mechanical-force-driven responses to the local scale. Here, we report mechanical-force-induced large-area, non-local, collective ferroelastic domain switching in PbTiO 3 epitaxial thin films by tuning the misfit-strain to be near a phase boundary wherein c/a and a 1 / a 2 nanodomains coexist. Phenomenological models suggest that the collective, c-a-c-a ferroelastic switching arises from the small potential barrier between the degenerate domain structures, and the large anisotropy of a and c domains, which collectively generates much larger response and large-area domain propagation. Large-area, non-local response under small stimuli, unlike traditional local response to external field, provides an opportunity of unique response to local stimuli, which has potential for use in high-sensitivity pressure sensors and switches.

36 MATERIALS SCIENCE↗
DOE OSTI2016

Ferroelastic switching in a layered-perovskite thin film

Here, a controllable ferroelastic switching in ferroelectric/multiferroic oxides is highly desirable due to the non-volatile strain and possible coupling between lattice and other order parameter in heterostructures. However, a substrate clamping usually inhibits their elastic deformation in thin films without micro/nano-patterned structure so that the integration of the non-volatile strain with thin film devices is challenging. Here, we report that reversible in-plane elastic switching with a non-volatile strain of approximately 0.4% can be achieved in layered-perovskite Bi 2 WO 6 thin films, where the ferroelectric polarization rotates by 90° within four in-plane preferred orientations. Phase-field simulation indicates that the energy barrier of ferroelastic switching in orthorhombic Bi 2 WO 6 film is ten times lower than the one in PbTiO 3 films, revealing the origin of the switching with negligible substrate constraint. The reversible control of the in-plane strain in this layered-perovskite thin film demonstrates a new pathway to integrate mechanical deformation with nanoscale electronic and/or magnetoelectronic applications.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2013

Non-volatile ferroelastic switching of the Verwey transition and resistivity of epitaxial Fe3O4/PMN-PT (011)

A central goal of electronics based on correlated materials or ‘Mottronics’ is the ability to switch between distinct collective states with a control voltage. Small changes in structure and charge density near a transition can tip the balance between competing phases, leading to dramatic changes in electronic and magnetic properties. In this work, we demonstrate that an electric field induced two-step ferroelastic switching pathway in (011) oriented 0.71Pb(Mg1/3Nb2/3)O3-0.29PbTiO3 (PMN-PT) substrates can be used to tune the Verwey metal-insulator transition in epitaxial Fe3O4 films in a stable and reversible manner. We also observe robust non-volatile resistance switching in Fe3O4 up to room temperature, driven by ferroelastic strain. These results provides a framework for realizing non-volatile and reversible tuning of order parameters coupled to lattice-strain in epitaxial oxide heterostructures over a broad range of temperatures, with potential device applications.

36 MATERIALS SCIENCE↗
DOE OSTI2017

Three-State Ferroelastic Switching and Large Electromechanical Responses in PbTiO 3 Thin Films

Leveraging competition between energetically degenerate states to achieve large field-driven responses is a hallmark of functional materials, but routes to such competition are limited. Here, a new route to such effects involving domain-structure competition is demonstrated, which arises from straininduced spontaneous partitioning of PbTiO 3 thin films into nearly energetically degenerate, hierarchical domain architectures of coexisting c/a and a 1 /a 2 domain structures. Using band-excitation piezoresponse force microscopy, this study manipulates and acoustically detects a facile interconversion of different ferroelastic variants via a two-step, three-state ferroelastic switching process (out-of-plane polarized c+ → in-plane polarized a → out-of-plane polarized c- state), which is concomitant with large nonvolatile electromechanical strains (≈1.25%) and tunability of the local piezoresponse and elastic modulus (>23%). It is further demonstrated that deterministic, nonvolatile writing/erasure of large-area patterns of this electromechanical response is possible, thus showing a new pathway to improved function and properties.

36 MATERIALS SCIENCE↗
DOE OSTI2016

Local probing of ferroelectric and ferroelastic switching through stress-mediated piezoelectric spectroscopy

The role of local strains is fundamental to the large effective piezoelectric and ferroelectric response of thin films. Therefore a method to investigate local strain-induced phenomena is imperative. Here, pressure induced domain reorganization is reported in lead zirconate titanate films with composition near the morphotropic phase boundary. An approach is thus demonstrated to simultaneously study the role of applied mechanical pressure on multiple local properties of the film. In particular, the modification of hysteresis loops collected at different tip pressures is consistent with first mostly ferroelastic and then ferroelectric dominated reorientation of domains under increasing applied pressure. The pressure induced domain writing is also investigated through phase field simulations where the applied pressure is generally found to increase the in-plane polarization of the domains with respect to the out-of-plane component, corroborating the experimental observations. The approach developed here has the potential to explore other hysteretic phenomena and phase transitions in a spatially resolved manner with varying local pressure.

36 MATERIALS SCIENCE↗
DOE OSTI2019

Deterministic Ferroelastic Domain Switching Using Ferroelectric Bilayers

Composition gradients, or dissimilar ferroelectric bilayers, demonstrate colossal electromechanical figures of merit attributed to the motion of ferroelastic domain walls. Yet, mechanistic understanding of polarization switching pathways that drive ferroelastic switching in these systems remains elusive. Here, the crucial roles of strain and electrostatic boundary conditions in ferroelectric bilayer systems are revealed, which underpin their ferroelastic switching dynamics. Using in situ electrical biasing in the transmission electron microscope (TEM), the motion of ferroelastic domain walls is investigated in a tetragonal (T) Pb(Zr,Ti)O 3 (PZT)/rhombohedral (R) PZT epitaxial bilayer system. Atomic resolution electron microscopy, in tandem with phase field simulations, indicates that ferroelastic switching is triggered by predominant nucleation at the triple domain junctions located at the interface between the T/R layers. Furthermore, this interfacial nucleation leads to systematic reversable reorientation of ferroelastic domain walls. Finally, deterministic ferroelastic domain switching, driven by the interfacial strain and electrostatic boundary conditions in the ferroelectric bilayer, provides a viable pathway toward novel design of miniaturized energy-efficient electromechanical devices.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2019

Kinetic control of tunable multi-state switching in ferroelectric thin films

Deterministic creation of multiple ferroelectric states with intermediate values of polarization remains challenging due to the inherent bi-stability of ferroelectric switching. In this work we show the ability to select any desired intermediate polarization value via control of the switching pathway in (111)-oriented PbZr 0.2 Ti 0.8 O 3 films. Such switching phenomena are driven by kinetic control of the volume fraction of two geometrically different domain structures which are generated by two distinct switching pathways: one direct, bipolar-like switching and another multi-step switching process with the formation of a thermodynamically-stable intermediate twinning structure. Such control of switching pathways is enabled by the competition between elastic and electrostatic energies which favors different types of ferroelastic switching that can occur. As a whole, our work reflects an alternative approach that transcends the inherent bi-stability of ferroelectrics to create non-volatile, deterministic, and repeatedly obtainable multi-state polarization without compromising other important properties, and holds promise for non-volatile multi-state functional applications.

36 MATERIALS SCIENCE↗
DOE OSTI2026

Linking Domain Structure Evolution at a Grain Boundary to Piezoelectric Response via Nano‐Diffraction

Electric-field-induced domain structure switching in a 1 𝜇⁢m -thick Pb 0.99 (Zr 0.45 Ti 0.55 ) 0.98 Nb 0.02 O 3 (Nb-doped PZT) bicrystal film was characterized in situ via nano-focused synchrotron diffraction. The epitaxial film was deposited on a (100) SrTiO 3 bicrystal substrate. The changes in domain structure were mapped within a 5 𝜇⁢m × 5 𝜇⁢m area at and around an in-plane tilt-type (23.6°) grain boundary with 50 nm spatial resolution. Rocking curves collected at each point of the mapped area provided the ability to reconstruct spatially-varying three-dimensional (3D) reciprocal space maps around the grain boundary. The 3D reciprocal space maps reveal how different tilted 𝑎 -type domain variants interact with the grain boundary as a function of increasing electric field. Initially, a subset of 𝑎 -type domain variants with their polarization vectors largely orthogonal to the grain boundary were found in greater abundance within 570 nm of the grain boundary, possibly due to X-ray beam-induced local increases in the electrical conductivity, but after the coercive field was exceeded, reconfiguration of the ferroelastic domains was observed. The spatially-varying reciprocal space maps also facilitated evaluation of the strain field across the mapped area, along with 𝑑 33,𝑓 . Significant spatial heterogeneity of strain and 𝑑 33,𝑓 are observed, especially at the coercive field, which was attributed to maintaining deformation compatibility and correlated ferroelastic switching.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Manipulating Ferroelectric Topological Polar Structures with Twisted Light

Abstract The dynamic control of non‐equilibrium states represents a central challenge in condensed matter physics. While intense terahertz fields drive metal‐insulator transitions and ferroelectricity via soft phonon modes, recent theory suggests that twisted light with orbital angular momentum (OAM) offers a distinct route to manipulate ferroelectric order and stabilize topological excitations including skyrmions, vortices, and Hopfions. Control of ferroelectric polarization in quasi‐2D CsBiNb 2 O 7 (CBNO) is demonstrated using non‐resonant twisted ultra‐violet (UV) light (375 nm, 800 THz). Combining in situ X‐ray Bragg coherent diffractive imaging (BCDI), twisted optical Raman spectroscopy, and density functional theory (DFT), three‐dimensional (3D) ionic displacements, strain fields, and polarization changes are resolved in single crystals. Operando measurements reveal light‐induced strain hysteresis under twisted light–a hallmark of nonlinear, history‐dependent ferroelastic switching driven by OAM. Discrete, irreversible domain transitions emerge as the topological charge ℓ is cycled, stabilizing non‐trivial domain textures including vortex‐antivortex pairs, Bloch/anti‐Bloch points, and merons. These persist after OAM removal, indicating a memory effect. Competing mechanisms are discussed, including multiphoton absorption, strain‐mediated polarization switching, and defect‐wall interactions. The findings establish structured light as a tool for deterministic, reversible control of ferroic states, enabling optically reconfigurable non‐volatile devices.

Chemistry↗
DOE OSTI2023

Applied in-plane strain effects on the polarization response of ferroelectric hafnium zirconium oxide thin films

The influence of biaxial stress on the maximum and remanent polarizations of 10 nm thick hafnium zirconium oxide thin films in metal–ferroelectric–metal capacitor structures has been quantified. In the as-prepared state with a nominal biaxial tensile strain of 0.20% and no applied extrinsic stress, remanent and maximum polarizations of 7.6 and 13.1 μC/cm 2 , respectively, were measured using a 2 MV/cm applied electric field. Reducing the intrinsic strain by 0.111% through the application of a compressive uniaxial stress results in a decrease in the remanent and maximum polarizations to 6.8 and 12.2 μC/cm 2 , respectively. Here, the polarization dependence on strain is nearly linear between these values. The observed variation in polarization with strain is consistent with strain impacting ferroelastic switching whereby in-plane tension increases the fraction of the short polar axis orienting out-of-plane, hence increasing out-of-plane polarization. In contrast, reducing the in-plane strain through compression results in an increase in the fraction of the long non-polar axis orienting out-of-plane, thereby decreasing out-of-plane polarization.

36 MATERIALS SCIENCE↗
DOE OSTI2015

In-situ structural investigations of ferroelasticity in soft and hard rhombohedral and tetragonal PZT

Despite the technological importance of hard and soft PZT, Pb(Zr,Ti)O{sub 3}, ceramics, the mechanisms of ferroelectric hardening and softening remain widely discussed in the literature. The hardening and softening phenomena have traditionally been investigated in relation with dielectric manifestations such as aging of the dielectric susceptibility and constriction of the polarization-electric field hysteresis loop. Here, we present a systematic investigation of the ferroelectric and ferroelastic properties of soft and hard PZT in both the tetragonal and rhombohedral phases. A particular focus has been devoted to ferroelastic domain switching by characterizing the macroscopic mechanical constitutive behavior and in-situ synchrotron X-ray diffraction during compression. It is demonstrated that variation of the ordering state of point defects in PZT ceramics affects the switching behavior of both ferroelectric and ferroelastic domains under mechanical or electrical fields. Softening of the mechanical and electrical properties of originally hard PZT ceramics was conferred by quenching the materials from above the Curie temperature. The present findings are discussed with respect to the current understanding of hardening-softening transitions in ferroelectric materials.

36 MATERIALS SCIENCE↗
DOE OSTI2014

Electric-field-controlled interface strain coupling and non-volatile resistance switching of La{sub 1-x}Ba{sub x}MnO₃ thin films epitaxially grown on relaxor-based ferroelectric single crystals

We have fabricated magnetoelectric heterostructures by growing ferromagnetic La{sub 1-x}Ba{sub x}MnO₃ (x=0.2, 0.4) thin films on (001)-, (110)-, and (111)-oriented 0.31Pb(In{sub 1/2}Nb{sub 1/2})O₃-0.35Pb(Mg{sub 1/3}Nb{sub 1/2})O₃-0.34PbTiO₃ (PINT) ferroelectric single-crystal substrates. Upon poling along the [001], [110], or [111] crystal direction, the electric-field-induced non-180° domain switching gives rise to a decrease in the resistance and an enhancement of the metal-to-insulator transition temperature T C of the films. By taking advantage of the 180° ferroelectric domain switching, we identify that such changes in the resistance and T C are caused by domain switching-induced strain but not domain switching-induced accumulation or depletion of charge carriers at the interface. Further, we found that the domain switching-induced strain effects can be efficiently controlled by a magnetic field, mediated by the electronic phase separation. Moreover, we determined the evolution of the strength of the electronic phase separation against temperature and magnetic field by recording the strain-tunability of the resistance [(ΔR/R){sub strain}] under magnetic fields. Additionally, opposing effects of domain switching-induced strain on ferromagnetism above and below 197 K for the La₀.₈Ba₀.₂MnO₃ film and 150 K for the La₀.₆Ba₀.₄MnO₃ film, respectively, were observed and explained by the magnetoelastic effect through adjusting the magnetic anisotropy. Finally, using the reversible ferroelastic domain switching of the PINT, we realized non-volatile resistance switching of the films at room temperature, implying potential applications of the magnetoelectric heterostructure in non-volatile memory devices.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗