Highly mismatched antiferroelectric films: Transition order and mechanical state

Antiferroelectric oxide thin-films: Fundamentals, properties, and applications

“…Considering that the AFE lattice distortion is inhomogeneous, a more complex strain distribution is possibly developed inside PbZrO 3 films. This may either arise from the surface effect where the surface energy is dominant in straining the thin films, or from intra-domain strain that helps to minimize the material micro twists near the interface [17].…”

“…3a, thin films exhibit a modified phase transition order with diffuse characteristics, while bulk PbZrO 3 undergoes a sharp first-order phase transition from an AFE phase to a PE phase at a critical temperature of ~232 • C. In addition, the transition temperature of PbZrO 3 thin film is found to be higher than that of bulk, which effectively broadens the temperature region of the AFE phase [13,15]. Based on temperature dependent X-ray diffraction, Kniazeva et al [17] reported an emergent in-plane M reflection, which coexists with AFE superstructure diffractions during temperature increasing. This manifests a new phase as an intermediate AFE state before the AFE to PE phase transition [17].…”

“…Based on temperature dependent X-ray diffraction, Kniazeva et al [17] reported an emergent in-plane M reflection, which coexists with AFE superstructure diffractions during temperature increasing. This manifests a new phase as an intermediate AFE state before the AFE to PE phase transition [17]. In contrast, Dufour et al [79] recently re-examined this phase transition but revealed another FE-like state that emerges in a large temperature window (100 K).…”

“…In the meantime, it is necessary to highlight another complication on the way of octahedral control of AFEs. Presently, conventional high-quality epitaxial lead-based AFE films were synthesized mostly on highly mismatched buffer layers and single-crystal substrates [15,17]. The pseudocubic lattice comparison of common perovskite AFE oxides, electrodes, and substrates at room temperature is drawn in Fig.…”

“…One typical example is that associated with the miniaturization of the microelectronic devices, the tendency of size effect from bulk to thin film makes the structural order parameters even more complex in the AFE, which is manifested by the deviation of cationic displacement from the antiparallel shifts as documented in prototypical AFE PbZrO 3 [16]. Pertinent to structure diversities in AFE thin films, this gives rise to abundant exotic phenomena, including the unusual structural phase transition [17] and complex ferrielectric-like behavior with non-zero remnant polarization [15,18]. A spring of recent experimental and theoretical findings have produced a plethora of diverse and occasionally conflicting accounts, which clearly demand a unified description to navigate the field.…”