Coupling of bias-induced crystallographic shear planes with charged domain walls in ferroelectric oxide thin films

Han, Myung Geun; Garlow, Joseph A.; Bugnet, Matthieu; Divilov, Simon; Marshall, Matthew S. J.; Dawber, Matthew; Fernández-Serra, Mariví; Botton, Gianluigi A.; Cheong, Sang‐Wook; Walker, Frederick J.; Ahn, Charles; Zhu, Yimei

doi:10.1103/physrevb.94.100101

Cited by 10 publications

(8 citation statements)

References 36 publications

(17 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To determine the as-grown polarization direction of the BFO film, we measured the displacements of the Fe ions with respect to the Bi sublattice for each unit cell in the atomic resolution STEM image using our in-house computing code (Figure 1d). [22] As the image intensity of HAADF image directly correlates to the total atomic number in the atomic column, in Figure 1d the brighter spots are the columns of Bi atoms (purple dots) while the weaker ones are Fe atoms (brown dots). Here, the spontaneous polarization direction (denoted by the yellow arrow) is antiparallel to the direction of the Fe displacement (denoted by blue arrows).…”

Section: Characterization Of the Initial Statementioning

confidence: 98%

Controlled Nucleation and Stabilization of Ferroelectric Domain Wall Patterns in Epitaxial (110) Bismuth Ferrite Heterostructures

Zhang

Tan

Sando

et al. 2020

Adv Funct Materials

Self Cite

View full text Add to dashboard Cite

Ferroelectric domain walls, topological entities separating domains of uniform polarization, are promising candidates as active elements for nanoscale memories. In such applications, controlled nucleation and stabilization of domain walls are critical. Here, using in situ transmission electron microscopy and phase-field simulations, a controlled nucleation of vertically oriented 109° domain walls in (110)-oriented BiFeO 3 (BFO) thin films is reported. In the switching experiment, reversed domains that are nucleated preferentially at the nanoscale edges of the "crest and sag" pattern-like electrode under external bias subsequently grow into a stable stripe configuration. In addition, when triangular pockets (with an in-plane polarization component) are present, these domain walls are pinned to form stable flux-closure domains. Phase field simulations show that i) field enhancement at the edges of the electrode causes site-specific domain nucleation, and ii) the local electrostatics at the domain walls drives the formation of flux closure domains, thus stabilizing the striped pattern, irrespective of the initial configuration. The results demonstrate how flux closure pinning can be exploited in conjunction with electrode patterning and substrate orientation to achieve a desired topological defect configuration. These insights constitute critical advancements in exploiting domain walls in next generation ferroelectronic devices.

show abstract

Section: Characterization Of the Initial Statementioning

confidence: 98%

Controlled Nucleation and Stabilization of Ferroelectric Domain Wall Patterns in Epitaxial (110) Bismuth Ferrite Heterostructures

Zhang

Tan

Sando

et al. 2020

Adv Funct Materials

Self Cite

View full text Add to dashboard Cite

show abstract

“…22 Presently, high-resolution and scanning TEM techniques allow for observation of individual atomic displacements and, hence, give information about the internal CDW structure. With these techniques, CDWs were documented in single crystals of LiNbO 3 , 27 YMnO 3 , 28 and (Ca,Sr) 3 Ti 2 O 7 , 29,30 thin films of BiFeO 3 , 8,[31][32][33] PbTiO 3 , 34 and PZT, [35][36][37][38][39][40] and ceramics of BiFeO 3 , 41 (K,Na)NbO 3 , 42 TmMnO 3 , 43 and LuMnO 3 . 43 TEM techniques, supplemented by analyses of the energy losses of electrons (EELS) were employed recently to detect elemental components of the material in the vicinity of CDWs.…”

Section: Cdw Observationsmentioning

confidence: 99%

“…43 TEM techniques, supplemented by analyses of the energy losses of electrons (EELS) were employed recently to detect elemental components of the material in the vicinity of CDWs. 30,[38][39][40][41] Other methods were also in use: scanning electron microscopy for observations of the intersections of CDWs with etched surfaces of LiNbO 3 crystals, 44 high-resolution X-ray photoemission electron microscopy to visualize and characterize conducting DWs in ErMnO 3 , 45 low-energy electron microscopy (electron backscattering) to image CDWs in LiNbO 3 crystals. 46 High-resolution TEM studies have provided crucial information about the widths of domain walls.…”

Section: Cdw Observationsmentioning

confidence: 99%

Physics and applications of charged domain walls

Bednyakov

Sturman

Sluka³

et al. 2018

npj Comput Mater

152

158

View full text Add to dashboard Cite

The charged domain wall is an ultrathin (typically nanosized) interface between two domains; it carries bound charge owing to a change of normal component of spontaneous polarization on crossing the wall. In contrast to hetero-interfaces between different materials, charged domain walls (CDWs) can be created, displaced, erased, and recreated again in the bulk of a material. Screening of the bound charge with free carriers is often necessary for stability of CDWs, which can result in giant two-dimensional conductivity along the wall. Usually in nominally insulating ferroelectrics, the concentration of free carriers at the walls can approach metallic values. Thus, CDWs can be viewed as ultrathin reconfigurable strongly conductive sheets embedded into the bulk of an insulating material. This feature is highly attractive for future nanoelectronics. The last decade was marked by a surge of research interest in CDWs. It resulted in numerous breakthroughs in controllable and reproducible fabrication of CDWs in different materials, in investigation of CDW properties and charge compensation mechanisms, in discovery of light-induced effects, and, finally, in detection of giant two-dimensional conductivity. The present review is aiming at a concise presentation of the main physical ideas behind CDWs and a brief overview of the most important theoretical and experimental findings in the field.

show abstract

“…We argue that this occurs, most probably, through the successive formation of ferroelectric nuclei (nanodomains) with an opposite polarization orientation, which gain in their quantity and size with increasing number of electrical pulses, as schematically depicted in Figure 2c. The nuclei formation might be preferentially initiated at the defect sites, 18,19 i.e., grain boundaries (because of the polycrystalline film) and the bottom and top interfaces of the ferroelectric. Following this interpretation, the succession of gate pulses will generate nanodomains up to a critical point, at which the polarization reversal of the entire grain occurs.…”

Section: Resultsmentioning

confidence: 99%

Accumulative Polarization Reversal in Nanoscale Ferroelectric Transistors

Mulaosmanovic

Mikolajick

Slesazeck

2018

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

The electric-field-driven and reversible polarization switching in ferroelectric materials provides a promising approach for nonvolatile information storage. With the advent of ferroelectricity in hafnium oxide, it has become possible to fabricate ultrathin ferroelectric films suitable for nanoscale electronic devices. Among them, ferroelectric field-effect transistors (FeFETs) emerge as attractive memory elements. While the binary switching between the two logic states, accomplished through a single voltage pulse, is mainly being investigated in FeFETs, additional and unusual switching mechanisms remain largely unexplored. In this work, we report the natural property of ferroelectric hafnium oxide, embedded within a nanoscale FeFET, to accumulate electrical excitation, followed by a sudden and complete switching. The accumulation is attributed to the progressive polarization reversal through localized ferroelectric nucleation. The electrical experiments reveal a strong field and time dependence of the phenomenon. These results not only offer novel insights that could prove critical for memory applications but also might inspire to exploit FeFETs for unconventional computing.

show abstract

Coupling of bias-induced crystallographic shear planes with charged domain walls in ferroelectric oxide thin films

Cited by 10 publications

References 36 publications

Controlled Nucleation and Stabilization of Ferroelectric Domain Wall Patterns in Epitaxial (110) Bismuth Ferrite Heterostructures

Controlled Nucleation and Stabilization of Ferroelectric Domain Wall Patterns in Epitaxial (110) Bismuth Ferrite Heterostructures

Physics and applications of charged domain walls

Accumulative Polarization Reversal in Nanoscale Ferroelectric Transistors

Contact Info

Product

Resources

About