Defect-Induced (Dis)Order in Relaxor Ferroelectric Thin Films

Abstract

The effect of intrinsic point defects on relaxor properties of 0.68 PbMg 1=3 Nb 2=3 O 3-0.32 PbTiO 3 thin films is studied across nearly 2 orders of magnitude of defect concentration via ex post facto ion bombardment. A weakening of the relaxor character is observed with increasing concentration of bombardment-induced point defects, which is hypothesized to be related to strong interactions between defect dipoles and the polarization. Although more defects and structural disorder are introduced in the system as a result of ion bombardment, the special type of defects that are likely to form in these polar materials (i.e., defect dipoles) can stabilize the direction of polarization against thermal fluctuations, and in turn, weaken relaxor behavior.

High Entropy Oxide Relaxor Ferroelectrics

“…65 As shown in Figure 3c, a Vogel-Fulcher relationship with an extrapolated freezing temperature of around 565 K corroborates the relaxor ferroelectric behavior of Ba(5B)O films. 64,66 The values of 𝐸𝐸 𝑎𝑎 (~0.16 eV) and 𝑓𝑓 0 (~3.18x10 12 Hz) extracted from the fit are similar to those values obtained for Pb- 64 and BTO-based relaxors. 39 given by the following equations as functions of the incidence optical polarization angle ϕ:…”

“…63 However, for relaxors, it is also common to find 1 < γ < 2 depending on the strength of the relaxor character. 64 The factor γ can be derived from the modified Curie-Weiss law;…”

Defects in complex oxide thin films for electronics and energy applications: challenges and opportunities

“…55 Formation and ordering of the defect dipoles can stabilize the direction of polarization against thermal fluctuations, and in turn, weaken the relaxor behavior in PMN-PT films. 56 Due to the formation of V C and/or V O , antisite cationic defects could emerge. For instance, swapping the cation positions between Sr 2+ and Ti 4+ to form anti-site defects of Sr Ti or Ti Sr , the paraelectric SrTiO 3 becomes ferroelectric at room temperature.…”

Growth mode and strain effect on relaxor ferroelectric domains in epitaxial 0.67Pb(Mg1/3Nb2/3)O3–0.33PbTiO3/SrRuO3 heterostructures

“…The presence of such a buttery-like shaped pattern in PMN-33PT lms is likely evidence of the presence of relaxor nanodomain structures. 10,26 However, the disappearance of the buttery-like shape for the highly strained lm (PMN-33PT/ SRO/DSO) is an indication of a change in the polar domains and can be explained by the reduction of the relaxor domains and the disorder within the PMN-33PT structure.…”

“…[10][11][12][13][14][15] Despite the great attention received by PMN-PT in thin lm form, in particular for energy harvesting, energy storage and cooling applications, [16][17][18][19][20][21] there is still a lack of knowledge regarding epitaxial thin lms, particularly concerning correlations between the local atomic structure/strain and physical properties. 10,[22][23][24][25][26][27] Thus, understanding of the domains in relaxor ferroelectric thin lms and their evolution under external parameters such as epitaxial strain is crucial for practical applications. While strain engineering in ferroelectric and multiferroic thin lms is known to be a powerful route to control, tune, and enhance the functional properties and also create/induce new exotic properties that do not exist in bulk, [28][29][30] few studies have been done on the effect of strain in relaxor ferroelectrics.…”