Article
Engineering, Chemical
Yongliang Zhang, Kevin Huang
Summary: Surface exchange kinetics and bulk diffusion of oxygen are crucial for the performance of oxygen electrocatalysis and electrochemical devices. In this study, oxygen surface exchange rates and bulk conductivity/chemical diffusivity were measured for three mixed oxide-ion and electron conductors. The results showed that one of the conductors exhibited the best oxygen electrocatalytic performance.
JOURNAL OF MEMBRANE SCIENCE
(2022)
Article
Chemistry, Physical
Arturas Jukna
Summary: This paper investigates energy dissipation and control of vortex motion in YBCO devices with partially deoxygenated structures. The results demonstrate that vortex motion can be effectively controlled by adjusting temperature, bias current, structure configuration, and oxygen distribution profile.
Article
Nanoscience & Nanotechnology
N. Porotnikova, A. Khrustov, A. Farlenkov, A. Khodimchuk, G. Partin, I Animitsa, N. Kochetova, D. Pavlov, M. Ananyev
Summary: The La2Mo2O9-La2Mo3O12 composite materials exhibit enhanced oxygen-ion conductivity compared to individual oxides, attributed to the segregation of different ions on the grain surface and the formation of a new phase La5Mo3O16 at the contact boundary of La2Mo2O9 and La2Mo3O12.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Materials Science, Ceramics
Duke P. C. Shih, Ainara Aguadero, Stephen J. Skinner
Summary: This study investigates the effect of A-site monovalent ions (K+ and Li+) on the electrical conductivity of NBT. The results show that partial replacement of Bi3+ with monovalent ions significantly improves the ionic conductivity, possibly due to an increase in oxygen vacancy concentration. The isotope exchange depth profile method confirms that oxygen ions are the main charge carriers.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
O. Merkulov, I. A. Leonidov, M. Patrakeev
Summary: The effect of substituting molybdenum for iron in triple-layer Ruddlesden-Popper ferrite Sr3LaFe3O10-delta has been studied, showing an increase in electron conductivity and ion conductivity under reducing conditions. The solubility of molybdenum in the material synthesized under an air atmosphere is found to be at about x = 0.2, leading to improved conductivity properties.
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
(2021)
Article
Materials Science, Ceramics
N. Tarasova, A. Galisheva, I. Animitsa, D. Korona, E. Abakumova, D. Medvedev
Summary: This study confirmed that the acceptor (calcium) and donor (indium) doping can significantly improve the properties of layered perovskite BaLa2In2O7 and increase the oxygen-ionic conductivity. It provides a new approach for the design of novel oxygen-ionic conductors.
CERAMICS INTERNATIONAL
(2022)
Article
Chemistry, Multidisciplinary
Daseob Yoon, Yujeong Lee, Gi-Yeop Kim, Youngho Kang, Si-Young Choi, Junwoo Son
Summary: A simple strategy to increase electrical conductivity in perovskite oxide semiconductors has been proposed through non-stoichiometry-driven metal exsolution, leading to enhanced carrier concentration in reduced films.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Chemistry, Physical
Jane Banner, Emily Ghosh, Srikanth Gopalan
Summary: The role of porosity in equilibration kinetics in electrical conductivity relaxation (ECR) experiments is highlighted in this study. The use of porous conductivity bars allows for quicker experiments and is critical for determining oxygen exchange kinetics. Both porous and dense bars show similar trends with oxygen partial pressure and differences between oxidation and reduction transients.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Chemistry, Physical
Sarah Eisbacher-Lubensky, Andreas Egger, Werner Sitte, Edith Bucher
Summary: The rare earth nickelate La2Ni0.9Co0.1O4+delta (LNCO) was synthesized via the citrate/EDTA method, and it was confirmed to have a single-phase structure. The substitution of nickel with cobalt in LNCO led to higher values of the surface exchange coefficient and slightly reduced electronic conductivity. The oxygen non-stoichiometry of LNCO was studied, and its thermal expansion coefficients were found to be similar to common solid electrolytes. LNCO shows potential as an air electrode in solid oxide cells.
SOLID STATE IONICS
(2023)
Article
Chemistry, Multidisciplinary
D. Cai, S. Yang, Z. Ma, L. Liu, D. Wang, J. Qian, Y. Li, T. E
Summary: Applying conductive coatings on non-conductive materials can effectively reduce hazards caused by static electricity during production. This study prepared Al-doped TiO2/graphene composites with excellent electrical conductivity by combining TiO2 homojunction, ion doping, heterojunction, and rod morphology. The introduction of Al3+ doubles the conductivity by generating oxygen vacancies and increasing carrier concentration, and it also enhances carrier transfer efficiency by creating new conductive pathways and increasing oxygen-containing functional groups. These findings provide new ideas for the preparation of conductive coatings.
MATERIALS TODAY CHEMISTRY
(2023)
Article
Electrochemistry
Jerome Laurencin, Jacinthe Gamon, Aurelien Flura, Giuseppe Sdanghi, Sebastien Fourcade, Vaibhav Vibhu, Jean-Marc Bassat
Summary: Mixed ionic electronic conductors (MIECs) oxides are used as electrode materials for solid oxide cell (SOC) application, as they combine high electronic conductivity as well as high oxygen diffusivity and oxygen surface exchange coefficients. The goal of this study was to compare the behavior of two types of reference materials, the oxygen deficient La-Sr-Fe-Co perovskites and the overstoichiometric lanthanide nickelates Ln2NiO4+& delta; (Ln = La, Pr, Nd), under different oxygen partial pressures.
Article
Chemistry, Physical
Sergey S. Nikitin, Alexey A. Markov, Ilia A. Leonidov, Mikhail Patrakeev
Summary: By thermodynamic analysis of defect equilibrium, the electrical conductivity of perovskite-type Sr1-xCexFeO3-δ was studied, showing a minor contribution of electrons localized on cerium ions to conductivity. An almost 10-fold decrease in ion conductivity was found with the increase of cerium content in Sr1-xCexFeO3-δ, attributed to a decrease in the mobility of oxygen ions, while having an insignificant effect on hole and electron conductivity.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Materials Science, Multidisciplinary
Romain Vauchy, Shun Hirooka, Masashi Watanabe, Keisuke Yokoyama, Tatsutoshi Murakami
Summary: In this study, the room temperature lattice parameters of fluorite-structured U1-yAmyO2 uranium-americium mixed oxides were compared with a crystallographic hybrid model. The complex charge compensation mechanisms in this solid solution were considered, and the effects of α self-irradiation, deviation from stoichiometry, and neptunium content on the lattice constants were estimated.
JOURNAL OF NUCLEAR MATERIALS
(2023)
Article
Materials Science, Ceramics
Z. H. Ren, Aditya Jain, L. N. Shi, H. Z. Zhou, F. G. Chen, Y. G. Wang
Summary: In this work, Bi non-stoichiometry is used to optimize the photostriction performance by controlling the oxygen vacancy concentration and the ferroelectric to relaxor phase transition temperature. The increase of Bi non-stoichiometry decreases the oxygen vacancy concentration, allowing for more effective interaction between the photo-generated carriers and the lattice, resulting in large photostriction and high photostriction efficiency. Moreover, the Bi non-stoichiometry induces the decrease of the TF-R and the decoupling of the A-O bond, which increases the polarizability of the unit cell and optimizes the photostriction macroscopically.
CERAMICS INTERNATIONAL
(2023)
Article
Chemistry, Physical
Jiayue Wang, Jing Yang, Alexander Karl Opitz, Dmitri Kalaev, Andreas Nenning, Ethan J. Crumlin, Jerzy T. Sadowski, Iradwikanari Waluyo, Adrian Hunt, Harry L. Tuller, Bilge Yildiz
Summary: Understanding the surface defect chemistry and its strain dependency is crucial in developing next-generation electrochemical devices. This study constructed the strain-dependent surface defect equilibria of mixed ionic-electronic conducting perovskite oxides and investigated the effect of strain on the reducibility of the surfaces. The findings were validated by first principles calculations and thermodynamic analyses, providing a quantitative determination of the surface defect chemistry.
CHEMISTRY OF MATERIALS
(2022)
Article
Physics, Applied
I. -E. Nylund, T. M. Raeder, P. E. Vullum, T. Grande
Summary: Chemical solution deposition is a versatile method for fabricating oxide films. The BaTiO3 films prepared on different SrTiO3 substrates were shown to be epitaxial and under tensile strain due to the difference in thermal expansion between the materials. Despite imperfections like edge dislocations and Ba-deficient boundaries, the films still exhibit excellent ferroelectric properties.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Nanoscience & Nanotechnology
Trygve M. Raeder, Theodor S. Holstad, Inger-Emma Nylund, Mari-Ann Einarsrud, Julia Glaum, Dennis Meier, Tor Grande
Summary: This study demonstrates the significant impact of crystal anisotropy on the ferroelectric properties of films, showing massive differences in dielectric and ferroelectric properties depending on the orientation. This has important implications for the engineering design of multilayer stacks, suggesting that other materials can be similarly engineered by utilizing crystal anisotropy.
Article
Engineering, Chemical
Roozbeh Mollaabbasi, Lene Jensberg Hansen, Tor Grande, Seyed Mohammad Taghavi, Houshang Alamdari
Summary: This study investigates the effects of fine particle concentration and temperature on the viscoelastic properties of the binder matrix in the formation of carbon anodes. It was found that increasing the fine particle concentration increases viscosity, while increasing temperature reduces viscosity. The three-element Maxwell model accurately predicts the elastic and viscous moduli of the binder matrix.
CANADIAN JOURNAL OF CHEMICAL ENGINEERING
(2022)
Article
Chemistry, Inorganic & Nuclear
Susanne Linn Skjaervo, Gary K. Ong, Ola Gjonnes Grendal, Kristin Hoydalsvik Wells, Wouter van Beek, Koji Ohara, Delia J. Milliron, Satoshi Tominaka, Tor Grande, Mari-Ann Einarsrud
Summary: Sodium niobate (NaNbO3) is attracting attention for its potential applications, particularly its unique optical properties. This study used in situ X-ray diffraction to observe the hydrothermal synthesis of NaNbO3 in real time, investigating the reaction kinetics and mechanisms with respect to temperature and NaOH concentration. The research identified several intermediate phases, established the relationship between them, and revealed distinct growth regimes for NaNbO3 at different temperatures.
INORGANIC CHEMISTRY
(2021)
Article
Materials Science, Multidisciplinary
Asem Hussein, Zhaohui Wang, Arne Petter Ratvik, Tor Grande, Houshang Alamdari
Summary: This study investigated the impact of bio-pitch on the electrochemical behavior of carbon anodes. The results showed that using bio-pitch as a binder slightly improved the electrochemical performance of the anodes.
METALLURGICAL AND MATERIALS TRANSACTIONS B-PROCESS METALLURGY AND MATERIALS PROCESSING SCIENCE
(2022)
Article
Materials Science, Multidisciplinary
Mtabazi G. Sahini, Kjell Wiik, Tor Grande
Summary: The study found that Co diffusion was significant in the La2NiO4+delta (LN) and CoO diffusion couples, while Ni diffusion was minor, leading to the formation of LaCoO3 and other compounds in the LN layer.
Article
Materials Science, Multidisciplinary
Inger-Emma Nylund, Maria Tsoutsouva, Tor Grande, Dennis Meier
Summary: In this study, we investigated the ferroelectricity of gadolinium molybdate using temperature-dependent X-ray diffraction. The results showed that the spontaneous polarization of gadolinium molybdate is induced by a structural instability in the ferroelectric phase, and the displacement of different cations follows different critical behavior.
PHYSICAL REVIEW MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Frode Hadegreesskjold Fagerli, Zhaohui Wang, Tor Grande, Henning Kaland, Sverre M. Selbach, Nils Peter Wagner, Kjell Wiik
Summary: This study demonstrates the use of hydrolyzation with a continuous gas flow to control the termination groups of multilayered MXene particles, resulting in nearly F-free and partly bare MXene materials. The hydrolyzation temperature was found to be crucial for controlling the properties and stability of the MXene materials. The results provide new insights into the thermal stability of MXene in hydrated atmospheres.
Article
Chemistry, Multidisciplinary
Viviann Hole Pedersen, Anders Bank Blichfeld, Kristine Bakken, Dmitry Chernyshov, Tor Grande, Mari-Ann Einarsrud
Summary: Aqueous chemical solution deposition (CSD) is a method for preparing oxide thin films, and this study investigates the formation mechanism of different crystal orientations using in situ synchrotron X-ray diffraction. The results highlight the importance of controlling nucleation and growth for film orientation and structure.
CRYSTAL GROWTH & DESIGN
(2022)
Article
Chemistry, Inorganic & Nuclear
Inger-Emma Nylund, Nora Statle Londal, Julian Walker, Per Erik Vullum, Mari-Ann Einarsrud, Tor Grande
Summary: The crystal structure of tetragonal tungsten bronzes with different cations occupying the A1 and A2 lattice sites has been systematically studied in this research. The occupancy of alkali cations on the A1 and A2 sites was determined by combining X-ray diffraction and scanning transmission electron microscopy with energy-dispersive spectroscopy. The results revealed that the cation occupancy on the A1 and A2 sites is influenced by the size variation of the alkali cations.
INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Trygve M. Raeder, Shuyu Qin, Rama K. Vasudevan, Tor Grande, Joshua C. Agar, Michael J. Zachman
Summary: Ferroelectrics are increasingly used in electronic devices for extreme environments. This study investigates the collective switching behavior of ferroelectric domain structures and discovers high-speed switching with ordered domain walls. The findings have implications for high-speed tunable dielectrics and low-voltage ferroelectric memories and logic.
Article
Chemistry, Physical
Inger-Emma Nylund, Caren Regine Zeiger, Ding Peng, Per Erik Vullum, Julian Walker, Mari-Ann Einarsrud, Tor Grande
Summary: A first-principles study of the tetragonal tungsten bronze (TTB) K4Bi2Nb10O30 has found in-plane polarization in contrast to the out-of-plane polarization found in most TTBs due to the effect of Bi 6s lone pair. By replacing the lead-containing material PN with KBN, a lead-free analog to morphotropic phase boundaries can potentially be achieved. The synthesis and properties of A4Bi2Nb10O30 (ABN, A = Na, K, Rb) were investigated to determine the structure and electrical properties, with particular focus on the role of the Bi 6s lone pair.
CHEMISTRY OF MATERIALS
(2023)
Article
Chemistry, Physical
Frode Haskjold Fagerli, Per Erik Vullum, Tor Grande, Zhaohui Wang, Sverre M. Selbach, Kjell Wiik, Nils Peter Wagner
Summary: Gas hydrolysation is demonstrated as a selective and efficient method to substitute F terminations with O-related terminations in multilayered MXene particles. The pre-intercalation of cations and the hydrolysation process enable structural pillaring and achieve significant F reduction without significant oxidation. This approach has potential for controlling the electrochemical performance of MXene particles.
Article
Chemistry, Multidisciplinary
Kristine Bakken, Anders B. Blichfeld, Inger-Emma Nylund, Dmitry Chernyshov, Julia Glaum, Tor Grande, Mari-Ann Einarsrud
Summary: This work reports on how heat treatment can be used to tailor the preferred orientation of BaTiO3 thin films deposited from aqueous chemical solution. The results demonstrate that the heating program greatly affects the crystallographic texture and preferred orientation of the films, and films with a high degree of preferred orientation show the strongest ferroelectric response.
Proceedings Paper
Electrochemistry
Samuel Senanu, Arne Petter Ratvik, Zhaohui Wang, Tor Grande
Summary: This study investigated the wetting behavior of carbon materials by molten electrolyte or metal during aluminum electrolysis. Results showed that polarization of the carbon cathode and the presence of aluminum significantly affected the wettability of a carbon material. The role of sodium in enhancing wetting behavior was also discussed.
LIGHT METALS 2021, 50TH EDITION
(2021)
