Enhanced strains by flexible nanoscale domain structure in BNKT-SBT relaxor ferroelectrics

Abstract

The high strain under a low electric field is critical for actuator applications, which has always been pursued. Here, enhanced strain properties were achieved by introducing Sr0.7Bi0.2TiO3 (SBT) into Bi1/2(Na0.84K0.16)1/2TiO3...

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

“…This is accompanied by a single current peak (P 1 ) within the J-E curve, characteristic of the NR phase. 44,45 With an increase in doping, there is a notable reduction in P r value, and the hysteresis loop assumes a "girdle" shape. 46 Additionally, double current peaks (P 2 and P 3 ) emerge in the J-E curves.…”

“…The hysteresis loop of BNKT‐0.0025BSN ceramics exhibits a substantial maximum polarization ( P m = 57.5 µC/cm 2 ), residual polarization ( P r = 50.8 µC/cm 2 ), coercive field ( E c = 32.5 kV/cm), and negative strain ( S neg = 0.13%). This is accompanied by a single current peak ( P 1 ) within the J‐E curve, characteristic of the NR phase 44,45 . With an increase in doping, there is a notable reduction in P r value, and the hysteresis loop assumes a “girdle” shape 46 .…”

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

“…[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. Additional clusters with almost no polarization magnitude are indicative of R 2 phase resulting from the centrosymmetric structure of R 2 phase, similar to that of cubic phase in the entropy-stabilized K 0.2 Na 0.8 NbO 3 -based ceramics.…”

Decoding the Atomic-Scale Structural Origin of Large Strain Performance in BNT-6BT Based Relaxor Ferroelectrics

“…The gradient of displacement and the displacement vector at the domain wall gradually changed its orientation to maintain head-to-tail structure, indicating a flexible domain structure. 25 According to the schematic directions in Figure 2e, the R and T phase coexistence of nanoscale domains can be observed, and the sizes of the nanodomains are around 2 nm. Compared with ferroelectric macrodomains in 94BNT-6BT ceramics, the polar nanoscale domains of 93BNT-6BT-1BZ ceramics have a smaller size and various orientations, and the percentage of T phase obviously increased.…”

“…The orientation of B-site displacement in Figure f shows polar nanodomains with various orientations. The gradient of displacement and the displacement vector at the domain wall gradually changed its orientation to maintain head-to-tail structure, indicating a flexible domain structure . According to the schematic directions in Figure e, the R and T phase coexistence of nanoscale domains can be observed, and the sizes of the nanodomains are around 2 nm.…”