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

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 organonitrate synthesis. The EPR spectra of HfxZr1-xO2-y nanopowders reveal the presence of paramagnetic defect centers, which may be hafnium and/or zirconium ions, which trapped an electron near an oxygen vacancy and changed their valence state from the non-paramagnetic +4 to the paramagnetic +3 state. The Raman spectra indicate the decisive role of surface defects, presumably oxygen vacancies, for all studied x = 1, 0.6, 0.5 and 0.4 At the same time the EELS analysis does not reveal any noticeable concentration of magnetic impurities in the HfxZr1-xO2-y nanopowders, and the X-ray diffraction analysis reveals the dominant presence of the orthorhombic phase. We observed that the quasi-static relative dielectric permittivity of the HfxZr1-xO2-y nanopowders overcomes 106 – 107 and related the colossal values with the superparaelectric state of the nanoparticles’ cores induced by the flexo-electro-chemical strains. It has been found that ultra-small HfxZr1-xO2-y nanoparticles reveal posistor effect and relatively large values of accumulated charge. Thus, obtained results open the way for creation of silicon-compatible ferroics − oxygen-deficient HfxZr1–xO2-y nanoparticles with superparamagnetic and superparaelectric properties, which may be used in advanced FETs and electronic logic elements.

Title: Magnetic properties and charge transport mechanisms in oxygen-deficient HfxZr1-xO2-y nanoparticles

Authors: Oleksandr S. Pylypchuk, Eugene A. Eliseev, Andrii V. Bodnaruk, Valentin V. Laguta, Yuri O. Zagorodniy, Andrei D. Yaremkevych, Denis O. Stetsenko, Oksana V. Leshchenko, Victor N. Pavlikov, Lesya Demchenko, Victor I. Styopkin, Myroslav V. Karpets, Olena M. Fesenko, Victor V. Vainberg, Anna N. Morozovska

Reference: Ceramics International, in press, 2026

DOI: https://doi.org/10.1016/j.ceramint.2026.03.015

Related Posts

Article 31 – Hysteresis phenomena in Cd2P2S6 layered crystals

2026-09-29

Abstract: The results of the study of the temperature dependence of the dielectric permittivity of Cd2P2S6 crystals are presented. It is shown that in the temperature range 80–420 K there are three regions in which hysteresis phenomena are observed. At high temperatures (T > 320 K) there is an activation change of the dielectric

Read more »

Article 30 – The influence of electric field on the anisotropic dispersion of the flexocoupling induced phonons and ferrons in van der Waals ferrielectrics

2026-09-29

Abstract: As it has been shown recently, the influence of the flexoelectric coupling (shortly “flexocoupling”) on the fluctuations of electric polarization and elastic strains can lead to the principal changes of the dispersion law of soft optical and acoustic phonons (shortly “flexophonons”) and ferrons (shortly “flexoferrons”) in van der Waals

Read more »

Article 29 – The impact of morphological structure and flexo-chemical strains on the electric transport mechanisms in molybdenum-disulfide-oxide nanoflakes

2026-09-29

Abstract: Electric conduction mechanisms in pressed powder samples consisting of molybdenum-disulfide-oxide (MoSxOy) nanoflakes depending on their content and structure have been investigated. The MoSxOy nanoflakes were synthesized in the temperature range of 130 °C–180 °C by reaction of (NH4)6Mo7O24 with thiourea in aqueous solution followed by aerial oxidation. The chemical

Read more »

Article 28 – Osteogenic Differentiation Triggered by Intracellular Magnetoelectric Stimulation of Core–Shell Nanotransducers under Remotely Applied Magnetic Fields

2026-09-29

Abstract: Magnetoelectric nanoparticles (MENPs), combining a magnetostrictive core with a piezoelectric shell, offer a promising route for remote-controlled biomedical applications by converting external magnetic fields into electric cues. However, the clinical translation of these materials remains limited due to the toxicity of high-performance piezoelectric materials, which typically contain lead. Previously,

Read more »

Article 27 – Colossal dielectric response of H⁡f𝑥⁡Z⁢r1−𝑥⁢O2 nanoparticles

2026-09-29

Abstract: We observed a colossal dielectric response of small (5–10 nm) oxygen-deficient H⁡f𝑥⁡Z⁢r1−𝑥⁢O2 nanoparticles (𝑥=1–0.4), prepared by solid-state organonitrate synthesis. The effective dielectric permittivity of the pressed H⁡f𝑥⁡Z⁢r1−𝑥⁢O2 nanopowders has a pronounced maximum at 38–88∘⁢C, the shape of which can be fitted by the Curie-Weiss type dependence modified for the

Read more »

Article 26 – Wireless Magnetoelectric Stimulation Platform Orchestrating Multicellular Coupling in Complex Neurovascularized Tissue Regeneration

2026-09-29

Abstract: Bone regeneration is a well-orchestrated biological process involving coordinate efforts of multiple cells, cytokines, and signals, among which nerves play a dominant role in regulating osteogenesis. Draw inspiration from the inherent electroactive features of bone and nerve, bioelectric implant providing wireless delivery of electrical stimulation (ES), is an emerging

Read more »

The Piezo2D project is financed by the European Union under the HORIZON.1.2 – Marie Skłodowska-Curie Actions (MSCA), topic HORIZON-MSCA-2022-SE-01-01 – MSCA Staff Exchanges 2022 (project number 101131229)