Ferroelectric phase-transition frustration near a tricritical composition point

Abstract

Phase transition describes a mutational behavior of matter states at a critical transition temperature or external field. Despite the phase-transition orders are well sorted by classic thermodynamic theory, ambiguous situations interposed between the first- and second-order transitions were exposed one after another. Here, we report discovery of phase-transition frustration near a tricritical composition point in ferroelectric Pb(Zr1-xTix)O3. Our multi-scale transmission electron microscopy characterization reveals a number of geometrically frustrated microstructure features such as self-assembled hierarchical domain structure, degeneracy of mesoscale domain tetragonality and decoupled polarization-strain relationship. Associated with deviation from the classic mean-field theory, dielectric critical exponent anomalies and temperature dependent birefringence data unveil that the frustrated transition order stems from intricate competition of short-range polar orders and their decoupling to long-range lattice deformation. With supports from effective Hamiltonian Monte Carlo simulations, our findings point out a potentially universal mechanism to comprehend the abnormal critical phenomena occurring in phase-transition materials.

Deciphering the phase transition-induced ultrahigh piezoresponse in (K,Na)NbO3-based piezoceramics

“…Note that a well-defined field-induced first-order phase transition is characterized by a very sharp change in sample temperature 58 , 59 . However, the observed temperature change is suppressed and smeared out, which is typically observed in the vicinity of the critical point, where a crossover from first-order to second-order phase transition takes places 60 – 62 . It has been demonstrated that polycrystalline materials feature a diffuse critical point due to their inherent inhomogeneity in grain orientation, and are therefore not expected to have a sharply-defined critical point as in single crystals 58 .…”

Structural Phase Transition and In-Situ Energy Storage Pathway in Nonpolar Materials: A Review

“…Finally, two recent works reported that mesoscale-domain engineering may greatly improve the energy storage density, e.g., from 12.2 to 18.5 J/cm 3 in NaNbO 3 -based relaxor AFE ceramics [44,166]. Pertinent to the beneficial hierarchical domain structures, structure-property relationship study of FE Pb(Zr,Ti)O 3 shows that this may arise from phase transition frustration near a tricritical point [167]. Together with the use of advanced computation and simulation methods, such as machine learning, we believe that carrying out cross-scale microstructure study may boost the development of energy storage materials and their device application.…”

Progress on Emerging Ferroelectric Materials for Energy Harvesting, Storage and Conversion

“…Near a tricritical point, the first‐order and second‐order transitions can even compete and give rise to a frustrated‐order transition, which leads to deviation from the classic mean‐field theory and a number of anomalies in critical exponents and structure. [ 75 ] These features indicate that the ferroelectric properties show great sensitivity to chemical composition, defect structure, boundary condition, and stimulus of external field. As a result, the ferroelectric polarization shows coupling to many other physical quantities and even their conjugate fields, for example, magnetism versus magnetic field ( M vs H ), strain versus stress (ε vs σ), defect concentration or conductivity versus chemical potential ( c vs μ) and beyond (Figure 2g).…”