Polarity Modulation Induced High Electrostrain Performance with Near-Zero Hysteresis in a (Sr_0.7Bi_0.2□0.1)TiO₃-Based System

Abstract

High-precision piezo actuators necessitate dielectrics with high electrostrain performance with low hysteresis. Polarity-modulated (Sr 0.7 Bi 0.2□0.1 )-TiO 3 -based ceramics exhibit extraordinarily discrete multiphase coexistence regions: (i) the relaxor phase coexistence (RPC) region with local weakly polar tetragonal (T) and pseudocubic (Pc) short-range polar nanodomains and (ii) the ferroelectric phase coexistence (FPC) region with T long-range domains and Pc nanodomains. The RPC composition features a specially high and pure electrostrain performance with nearzero hysteresis (S ∼ 0.185%, Q 33 ∼ 0.038 m 4 •C −2 ), which is double those of conventional Pb(Mg 1/3 Nb 2/3 )O 3 -based ceramics. Particular interest is paid to the RPC and FPC with multiscale characterization to unravel local structure−performance relationships. Guided by piezoelectric force microscopy, scanning transmission electron microscopy, and phase-field simulations, the RPC composition with multiphase low-angle weakly polar nanodomains shows local structural heterogeneity and contributes to a flat local free energy profile and thus to nanodomain switching and superior electrostrain performance, in contrast to the FPC composition with a macroscopic domain that shows stark hysteresis. This work provides a paradigm to design high-precision actuator materials with large electrostrain and ultralow hysteresis, extending our knowledge of multiphase coexistence species in ferroelectrics.

Large electrostrain achieved in BNKT‐based ceramics by the adjustment of phase boundary with Ba(Sn0.70Nb0.24)O3 addition

“…The introduction of BSN induces noticeable changes in the shape and size of the domains. 63 In BNKT-0.0075BSN ceramics, a coexistence of ferroelectric domains and polar nano-microregions (PNRs) is evident. 64,65 With an increase in BSN content, the size and number of ferroelectric domains decrease and large ferroelectric domain structures are almost absent.…”

“…Figure 7A,B depicts the evolution of BNKT‐ x BSN structural domains characterized by piezoresponse force microscopy (PFM). The introduction of BSN induces noticeable changes in the shape and size of the domains 63 . In BNKT‐0.0075BSN ceramics, a coexistence of ferroelectric domains and polar nano‐microregions (PNRs) is evident 64,65 .…”

Synergy of Oxygen Octahedra Distortion and Polar Nanodomains Induced Emergent Electrocaloric Effect in NaNbO3-Based Ceramics

“…55 As depicted in Figure 5g− associated with an average size of polar nanodomains. 61, 62 The average autocorrelation functions C(r) are plotted with the average autocorrelation fitting, as shown in Figure 5j. The experimental data match well with the average autocorrelation fitting, and the fitted <ξ> value is presented in Figure 5k.…”

Superb Energy Storage Capability for NaNbO3‐Based Ceramics Featuring Labyrinthine Submicro‐Domains with Clustered Lattice Distortions

“…[48,49] Levin et al suggested that ½(ooe), ½(ooo) and ½(eoe) superlattices are manifested for orthorhombic Pb2 1 m symmetry with √ 2a p × √ 2a p × 2a p unit cell (alternative setting P2 1 ma). [50] Besides, atomic positions along [100] c are further analyzed using CalAtom Software [51,52] and then atomic displacement vectors are mapped in Figure 3e. According to schematic P directions of T and O phases along [100] c (Figure 3f [53,54] ), the visualized polar clusters of 1-2 nm with the same P T and P O directions are representative of T and O phases, respectively.…”

“…Besides, atomic positions along [100] c are further analyzed using CalAtom Software [ 51,52 ] and then atomic displacement vectors are mapped in Figure 3e. According to schematic P directions of T and O phases along [100] c (Figure 3f [ 53,54 ] ), the visualized polar clusters of 1–2 nm with the same P T and P O directions are representative of T and O phases, respectively.…”