Article 7 – Ferro-ionic states and domains morphology in HfxZr1−xO2 nanoparticles

Abstract:

Unique polar properties of nanoscale hafnia-zirconia oxides (Hf_xZr_1−xO₂) are of great interest for condensed matter physics, nanophysics, and advanced applications. These properties are connected (at least partially) to the ionic–electronic and electrochemical phenomena at the surface, interfaces, and/or internal grain boundaries. Here, we calculated the phase diagrams, dielectric permittivity, spontaneous polar, and antipolar ordering, as well as the domain structure morphology in Hf_xZr_1−xO₂ nanoparticles covered by ionic–electronic charge originating from surface electrochemical adsorption. We revealed that the ferro-ionic coupling supports the polar long-range order in nanoscale Hf_xZr_1−xO₂, induces, and/or enlarges the stability region of the labyrinthine domains toward smaller sizes and smaller environmental dielectric constant at low concentrations of the surface ions. The ferro-ionic coupling causes the transition to the single-domain ferro-ionic state at high concentrations of the surface ions. We predict that the labyrinthine domain states, being multiple-degenerated, may significantly affect the emergence of the negative differential capacitance state in the nanograined/nanocrystalline Hf_xZr_1−xO₂ films.

Title: Ferro-ionic states and domains morphology in HfxZr1−xO2 nanoparticles

Authors: Eugene A. Eliseev, Sergei V. Kalinin, Anna N. Morozovska

Reference: J. Appl. Phys. 137, 034103 (2025)

DOI:https://doi.org/10.1063/5.0243067

Article 17 – Interfacially coupled Bi2WO6@WS2-PVDF based film for sonophotocatalytic trimethoprim removal: From material engineering to surface- and groundwater applications

2026-07-13

Abstract: Pharmaceutical contaminants in water represent a growing environmental concern due to their persistence and potential ecotoxicity. In this study, a hybrid Bi2WO6@WS2-PVDF-HFP (Poly(vinylidene fluoride-co-hexafluoropropylene) film was developed and evaluated as a sonophotocatalytic platform for the efficient degradation of trimethoprim (TMP) in both model and real water matrices. Comprehensive structural,

Article 16 – Electrostriction-driven phase instability enables giant pseudo-piezoelectricity in Hf0.5Zr0.5O2X

2026-07-13

Abstract: The electromechanical properties of hafnium zirconium oxide fluorite (Hf0.5Zr0.5O2, HZO) remain largely unexplored despite its widespread use as a ferroelectric in CMOS-compatible devices. Here, we demonstrate that electrostriction-driven phase instability enables a giant pseudo-piezoelectric response in epitaxial HZO thin films. Above a critical field of 24 kilovolts per centimeter, field-induced

Article 15 – Photo-pyroelectric Effect in Piezoelectric Polymer Composites: An Innovative Pathway for Advanced Technologies

2026-03-20

Abstract: The development of smart materials that can react to external stimuli and provide controlled and frequently reversible responses is facilitated by the coupling of physical effects. In this work, a photo-pyroelectric effect based on a piezoelectric polyvinylidene fluoride-trifluoroethylene (P(VDF-TrFE)) polymer composite with fullerene C60 incorporated at different concentrations (1, 3,

Article 14 – Magnetic properties and charge transport mechanisms in oxygen-deficient HfxZr1-xO2-y nanoparticles

2026-03-11

Abstract: Study of nanoscale hafnia-zirconia physical properties is the key topic in fundamental and applied science. However, charge transport mechanisms and magnetic properties of HfxZr1-xO2 nanoparticles are very poorly studied both theoretically and experimentally. In this work we observed a superparamagnetic-like and superparaelectric-like response of ultra-small HfxZr1-xO2-y nanoparticles prepared by the solid-state

Article 13 – Electro-Chemo-Mechanical Coupling in Hf0.5Zr0.5O2 Ferroionic Heterostructures

2026-03-11

Abstract: Ferroelectricity in Hf0.5Zr0.5O2 (HZO) originates from a polymorphic landscape where the metastable orthorhombic phase competes with monoclinic and tetragonal forms, making functional properties highly sensitive to structural instability. Recent strategies have exploited ionic-vacancy mechanisms, either through redox interactions with the environment or by employing ferroionic heterostructures, to enhance ferroelectric performance.

Article 12 – Flexocoupling-induced phonons and ferrons in van der Waals ferroelectrics

2025-08-05

Abstract: The contribution of flexoelectric coupling to the long-range order parameter fluctuations in ferroics can be critically important to the ferron dispersion and related polar, pyroelectric, and electrocaloric (EC) properties. Here, we calculate analytically the dispersion relations of soft optic and acoustic flexocoupling-induced phonons and ferrons by incorporating the flexoelectric