Domain Wall Orientations in Ferroelectric Superlattices Probed with Synchrotron X-Ray Diffraction

Abstract

Ferroelectric domains in PbTiO_{3}/SrTiO_{3} superlattices are studied using synchrotron x-ray diffraction. Macroscopic measurements reveal a change in the preferential domain wall orientation from {100} to {110} crystallographic planes with increasing temperature. The temperature range of this reorientation depends on the ferroelectric layer thickness and domain period. Using a nanofocused beam, local changes in the domain wall orientation within the buried ferroelectric layers are imaged, both in structurally uniform regions of the sample and near defect sites and argon ion-etched patterns. Domain walls are found to exhibit a preferential alignment with the straight edges of the etched patterns as well as with structural features associated with defect sites. The distribution of out-of-plane lattice parameters is mapped around one such feature, showing that it is accompanied by inhomogeneous strain and large strain gradients.

Domain structure and dielectric properties of metal-ferroelectric superlattices with asymmetric interfaces

“…In these artificially layered materials, ordered nanoscale domains form within the ultrathin ferroelectric layers to minimize the depolarization field energy associated with the unscreened polarization [1][2][3]. Motivated by theoretical predictions of complex polarization structures, unusual switching behavior, and high-frequency dynamics [4][5][6][7][8][9], the properties of nanodomains in ferroelectric superlattices have been widely investigated using laboratory and synchrotron x-ray diffraction as a function of applied field, temperature, and optical excitation [3,[10][11][12][13][14][15][16][17][18][19][20][21]. Direct imaging of the domains using scanning probe techniques is challenging due to their small sizes and buried nature, and it has been mainly restricted to ferroelectric-dielectric bilayers and trilayers, or superlattices with larger domains [22][23][24].…”

Large Electric‐Field‐Induced Strain Close to the Surface in Barium Titanate Studied by Atomic‐Scale In Situ Electron Microscopy

“…The lattice parameters of a material under an electric field can be measured in bulk and thin-film specimens with sufficiently large volume by using in situ X-ray diffraction [7][8][9][10] . Furthermore, nanoprobe X-ray diffraction has advanced rapidly in recent years [11][12] and has been used to investigate the local structures of ferroelectric materials [13][14] . This capability should help in studying nanoscale polar structures such as "polar nanoregions" [15,16] and lamellar-like nanodomains [17][18][19][20] , as well as defect structures such as surface, interface, and grain boundaries, along with nanoscale objects such as nanoparticles [21,22] .…”

Design and Manipulation of Ferroic Domains in Complex Oxide Heterostructures

“…Hadjimichael et al [119] recently demonstrated the potential of diffuse scattering for nanoscale investigation of domain and domain wall architecture in ferroelectric PTO/STO superlattices. Local reciprocal space maps (RSM) were measured around the out-of-plane (002) Bragg PTO reflection.…”

“…Spatially scanning the area at the x-ray angles of the satellite peaks in the (100), (110) and (010) direction around the defect shows the domain type dependence on the defect shape, i.e., the domains lie parallel to the lines of the defect. Reprinted with permission from [119]. ( b ) SHG images of voltage-poled 180° domain walls in PZT films grown on SRO buffered (DSO) show the total in-plane polarization, the polarization parallel to the ( c ) [001] DSO direction and ( d ) [110] DSO direction.…”