Disrupting long-range polar order with an electric field

Abstract

Electric fields are known to favor long-range polar order through the aligning of electric dipoles in relation to Coulomb's force. Therefore, it would be surprising to observe a disordered polar state induced from an ordered state by electric fields. Here we show such an unusual phenomenon in a polycrystalline oxide where electric fields induce a ferroelectric to relaxor phase transition. The non-ergodic relaxor phase with disordered dipoles appears as an intermediate state under electric fields during polarization reversal of the ferroelectric phase.Using the phenomenological theory, the underlying mechanism for this unexpected behavior can be attributed to the slow kinetics of the ferroelectric to relaxor phase transition, as well as its competition against domain switching during electric reversal. The demonstrated material could also serve as a model system to study the transient stages in first-order phase transitions; the slow kinetics does not require the use of sophisticated ultrafast tools.

Giant electrostrain accompanying structural evolution in lead-free NBT-based piezoceramics

“…[21][22][23][24]39 For SBT2 sample, two additional current peaks (P 2 ) appear at lower-field region, suggesting the presence of relaxor phase and a twostep transition processes during loading or unloading of external field: the P 2 peak corresponds to the ferroelectricrelaxor transition with the disruption of polar domains into nanodomains, while the P 1 peak indicates the relaxorferroelectric transition with the coalescence and re-formation of large domains. [21][22][23][24][39][40][41] Furthermore, the increase in fraction of ergodic relaxor phase moves the P 2 peak to near zero field for SBT5 sample, similar to those of SBT0 and SBT2 samples at Please do not adjust margins Please do not adjust margins their T FR (inset of Fig. 6(a)), revealing the critical transition nature of SBT5 composition.…”

Pressure‐induced ferroelectric‐relaxor phase transition in (Bi0.5Na0.5)TiO3‐based ceramics

“…Thus, the enhanced P FR can be attributed to the increased fraction of the FE phase. On the other hand, the macrodomains are irreversibly formed within the disordered nanodomains or PNRs under a high electric field . Because of the stronger interactions between polar clusters and the strain induced by domain reorientation, a much higher P FR value must be applied to overcome the poling effect.…”

Large electrocaloric responses in [Bi1/2(Na,K)1/2]TiO3‐based ceramics with giant electro‐strains

“…For each test temperature between 20°C and 100°C, there are four anomalies within one full cycle, two J 1 and two J 2 . J 1 corresponds to the forward phase transition while J 2 represents the backward process . Heated up from the vicinity of T d (20°C), the forward phase transition tends to become harder, that is, E J1 (the electric field at J 1 ) is supposed to increase .…”

“…J 1 corresponds to the forward phase transition while J 2 represents the backward process. 48 Heated up from the vicinity of T d (20°C), the forward phase transition tends to become harder, that is, E J1 (the electric field at J 1 ) is supposed to increase. 49 In BNKT-2.5Nb, E J1 increases linearly between 20°C and 50°C.…”