Characterization of adsorption properties inherent to zirconia dioxide for different positions of yttrium in the ZrO2–Y2O3 lattice

Funding Information: This project has been supported by funding from the European Union’s Horizon 2020 research and innovation program in accord to the Marie Sklodovska-Curie grant agreement 871284. Publisher Copyright: © 2022, V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine.Presented in this paper is theoretical studying redistribution of electric charges in the layer of a tetragonal plate of yttrium-stabilized zirconia based on the position of yttrium atom in the crystal lattice for both dry and humid ambient atmosphere. The density functional theory with local density approximation (DFT-LDA) has been employed for this modelling. Calculations have been performed for layer-by-layer electron density distribution over the thickness of an infinite plate 001 of yttrium-stabilized tetragonal zirconium dioxide, which show that a change in the position of stabilizing yttrium atom and its symmetry in the layer leads to changing the total energy of zirconium dioxide both for the dry 001 surface and for the hydrated one. It has been ascertained that the surface charge density for the 001-surface of an infinite tetragonal zirconia plate increases in proportion to the degree of hydration.publishersversionpublishe

Reversible Martensitic Phase Transition in Yttrium-Stabilized ZrO2 Nanopowders by Adsorption of Water

Funding: This work was supported by H2020/MSCA/RISE/SSHARE number 871284 project and the RO-JINR Grant No. 367/2021 item 27 and RO-JINR Projects № 366/2021 items 57, 61, 83, 85. Publisher Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland.The present study was aimed at revealing the influence of the mechanical stress induced by water molecule adsorption on the composition of crystalline phases in the ZrO2 + 3 mol% Y2O3-nanoparticles. Three basic methods were used to determine the phase transition: Neutron diffraction, Raman microspectroscopic scanning, and X-ray diffraction. The fact of reversible phase-structural β → α transformation and the simultaneous presence of two polymorphic structural modifications (β is the phase of the tetragonal syngony and α of monoclinic syngony in nanosized particles (9 nm)) under normal physical conditions was established by these methods. An assumption was made regarding the connection of the physical mechanism of transformation of the extremely nonequilibrium surface of nanoparticles with electronic exchange of the material of the near-surface layer of nanoparticles with the adsorption layer through donor-acceptor interaction. The principal possibility of creating direct-acting hydroelectric converters based on nanoscale YSZ (Yttria-Stabilized Zirconia) systems due to the reversible character of the considered effect was shown.publishersversionpublishe

The Rectifying Contact of Hydrated Different Size YSZ Nanoparticles for Advanced Electronics

The paper considers the new effects of the nanoscale state of matter, which open up prospects for the development of electronic devices using new physical principles. The contacts of chemically homogeneous nanoparticles of yttrium-stabilized zirconium oxide (ZrO2—x mol% Y2O3, x = 0, 3, 4, 8; YSZ) with different sizes of 7.5 nm and 9 nm; 7.5 nm and 11 nm; and 7.5 nm and 14 nm, respectively, was studied on direct current using nanostructured objects in the form of compacts obtained by high-hydrostatic pressure (HP-compacts of 300MPa). A unique size effect of the nonlinear (rectifying-type contact) dependence of the electrical properties (in the region U < 2.5 V, I ≤ 2.7 mA) of the contact of different-sized YSZ nanoparticles of the same chemical composition is revealed, which indicates the possibility of creating semiconductor structures of a new type (homogeneous electronics). The electronic structure of the near-surface regions of nanoparticles of studied oxide materials and the possibility of obtaining specifically rectifying properties of the contacts were studied theoretically. Models of surface states of the Tamm-type are constructed considering the Coulomb long-range action. The discovered energy variance and its dependence on the curvature of the surface of nanoparticles made it possible to study the conditions for the formation of a contact potential difference in cases of nanoparticles of the same radius (synergistic effect), different radii (doped and undoped variants), as well as to discover the possibility of describing a group of powder particles within the Anderson model. The determined effect makes it possible to solve the problem of diffusion instability of semiconductor heterojunctions and opens up prospects for creating electronic devices with a fundamentally new level of properties for use in various fields of the economy and breakthrough critical technologies