Article
Materials Science, Ceramics
Shen J. Dillon, Yu-Feng Shen, Gregory S. Rohrer
Summary: By investigating the variation of grain boundary energy, the characteristics of grain boundaries in 8% yttria-stabilized zirconia were identified, with a focus on the impact of [100] orientation and [100] twist boundaries. The study results indicate that by manipulating the microstructure to increase the relative areas of [100] twist boundaries, the oxygen ion conductivity of the material can be enhanced.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2022)
Article
Materials Science, Ceramics
Vladimir Prajzler, Karel Maca, Premysl St'astny, Richard Todd
Summary: The study found that in flash sintered 3YSZ ceramics, the microstructural homogeneity decreased with increasing direct current density and dwell time in a flash state, eventually leading to abnormal grain growth.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2022)
Article
Materials Science, Multidisciplinary
Yanhao Dong, Yimeng Huang, Dong Ding, Wei Wu, Xiahui Yao, Ju Li
Summary: This study uses first-principles calculations to illustrate the chemical nature and local structural features of hole states in oxidized YSZ, identifying three types of hole states. The implications of these findings on various experimental observations are discussed, shedding light on the understanding of electronic conductivity and hole carriers in YSZ.
Article
Materials Science, Ceramics
Andreas Flaureau, Alicia Weibel, Geoffroy Chevallier, Claude Estournes
Summary: In this study, densification and grain growth mechanisms of Yttria-Stabilized Zirconia sintered by Spark Plasma Sintering were investigated. The mechanisms were determined based on sintering trajectories of different commercial submicronic powders with varying yttria amounts and particle sizes. Densification was found to occur through grain boundary sliding and other mechanisms, while grain growth followed a power law in fully densified ceramics.
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
(2021)
Article
Materials Science, Ceramics
Benjamin Kowalski, Jamesa Stokes, Patrick. E. E. Albert, Pete. E. E. Lauer, Douglas. E. E. Wolfe
Summary: This study investigates the effect of grain size, areal density, and aspect ratio on the infiltration of CMAS into yttria stabilized zirconia. The infiltration depths ranged from 6 up to 85 μm depending on the test conditions.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2023)
Article
Chemistry, Inorganic & Nuclear
Ya-Zhe Xing, Yin-Ni Men, Xiao Feng, Ji-Hua Geng, Zhi-Rui Zou, Fu-Hua Chen
Summary: The effect of CuO addition on the microstructure and ionic conductivity of 8YSZ was investigated. The results show that with increasing CuO doping content, the lattice parameter decreases, while the relative density and mean grain size increase. 2 mol% CuO-doped 8YSZ exhibits the lowest activation energy and the highest ionic conductivity.
JOURNAL OF SOLID STATE CHEMISTRY
(2022)
Article
Nanoscience & Nanotechnology
Sangbong Ryu, In Won Choi, Yang Jae Kim, Sanghoon Lee, Wonyeop Jeong, Wonjong Yu, Gu Young Cho, Suk Won Cha
Summary: In order to improve the sluggish oxygen-ion conduction in the electrolytes of low-temperature solid-oxide fuel cells (SOFCs), researchers have focused on fabricating thin-film electrolytes. This study used reactive sputtering to deposit yttria-stabilized zirconia (YSZ) as a thin-film electrolyte. By varying the sputtering chamber pressure, the researchers were able to achieve high surface area, large grain size, and residual tensile stress, resulting in improved electrolyte performance. The thin-film SOFC with YSZ deposited at 15 mTorr exhibited the highest maximum power density at low operating temperature. Evaluation: 8 out of 10.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Nanoscience & Nanotechnology
Sangbong Ryu, In Won Choi, Yang Jae Kim, Sanghoon Lee, Wonyeop Jeong, Wonjong Yu, Gu Young Cho, Suk Won Cha
Summary: In order to improve the performance of low-temperature solid-oxide fuel cells (SOFCs), researchers have focused on fabricating thin-film electrolytes to enhance oxygen-ion conduction. In this study, yttria-stabilized zirconia (YSZ) was deposited via reactive sputtering process to achieve high-performance electrolytes. By adjusting the sputtering chamber pressure, the researchers were able to obtain high surface area, large grain size, and residual tensile stress, resulting in improved performance of the electrolyte.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Materials Science, Ceramics
Rushi K. Kathiria, Seohyeon Jo, Rishi Raj, Devinder Yadav
Summary: Specimens triggered with flash heating can be held in Stage III both outside the furnace and immersed in liquid nitrogen, with the possibility of locking this state by turning off the power. Materials in this state exhibit metallic behavior, with a conductivity of approximately 11 S/m at room temperature, and enable ex-situ characterization of structural changes induced by flash activation.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2022)
Article
Materials Science, Multidisciplinary
M. Faryna, K. Glowinski
Summary: This study computed the probability distributions of grain boundaries based on their macroscopic boundary parameters for yttria-stabilized zirconia samples with different grain sizes. The datasets collected using 3D EBSD technique provided both grain misorientation and boundary plane parameters. The distributions of the five parameters were computed using kernel density estimation and showed several prominent peaks that exceeded the level of random distribution. The collected dataset, containing 64,506 distinct grain boundaries, is the largest of its kind for zirconia and allowed for the investigation of rare boundaries.
Article
Materials Science, Ceramics
Lukas Theis, Frank Kern
Summary: Partially stabilized zirconia ceramics with different gadolinia content were prepared by co-milling, spray granulation, axial pressing, and pressureless sintering. The redistribution of stabilizers at high sintering temperatures was observed by XRD. Substituting gadolinia for yttria reduced the stabilizer content in the tetragonal phase and increased the tetragonality, transformability, and toughness of the materials, while decreasing the hardness. The cubic content increased with increasing gadolinia content, as predicted by thermodynamic considerations.
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Volodymyr Kulyk, Zoia Duriagina, Andrii Kostryzhev, Bogdan Vasyliv, Olexandra Marenych
Summary: This study investigates the influence of sintering temperature and yttria percentage on the microstructure and mechanical behavior of YSZ ceramics. The ceramics sintered at 1550 degrees C and 1450 degrees C exhibited the highest levels of strength.
APPLIED SCIENCES-BASEL
(2022)
Article
Chemistry, Physical
Marko Jakovac, Teodoro Klaser, Arijeta Bafti, Zeljko Skoko, Luka Pavic, Mark Zic
Summary: This study investigates the impact of Y3+ addition on the properties of zirconia materials, including grain size, grain boundary, lattice parameter values, and electrical parameters. The results show that Y3+ addition increases grain size and density, and influences the composition of the zirconia phases. Higher concentrations of Y3+ ions mainly incorporate into the tetragonal phase, resulting in decreased resistivity and increased capacitance in the grain boundaries.
Article
Materials Science, Ceramics
Jun Asai, Mongkol Bumrungpon, Toshiya Tsubochi, Takayuki Kanaya, Masaya Tachii, Toshiki Maeda, Kazuhiro Hasezaki
Summary: The study investigated the effects of tellurium addition on the thermoelectric properties of Bi0.3Sb1.7Te3.0, revealing that samples fabricated with YSZ milling media had narrower solid-solubility limits and exhibited the highest dimensionless figure of merit at room temperature.
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
(2021)
Article
Chemistry, Physical
Batuhan Bal, Aligul Buyukaksoy
Summary: The study focuses on using yttria doped bismuth oxide ceramics as electrolyte supports and applying zirconia coatings to prevent reduction upon contact with hydrogen. However, the reaction between Zr source and YDB substrate as well as the choice of polymerization extent play crucial roles in crack formation and film conductivity.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Chemistry, Multidisciplinary
Kendra S. Belthle, Ute N. Gries, Michael P. Mueller, Dennis Kemp, Abhinav Prakash, Marc-Andre Rose, Jacqueline M. Boergers, Bharat Jalan, Felix Gunkel, Roger A. De Souza
Summary: The properties and concentrations of native point defects in the perovskite oxide BaSnO3 were studied using a combination of experiments and simulations. The results provide insights into the material's characteristics and stability.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Chemistry, Physical
Hans F. Wardenga, Katharina N. S. Schuldt, Stephan Waldow, Roger A. De Souza, Andreas Klein
Summary: The study investigated the influence of different doping methods, concentrations, and surface orientations on the surface Fermi level positions, ionisation potentials, and work functions of CeO2. It was found that the ionisation potentials are significantly affected by doping and oxygen activity, while the work functions are largely unaffected. In terms of oxygen surface exchange coefficients, similar magnitudes were observed under different conditions.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Elisabeth Robens, Robert Rauschen, Johannes Kaub, Jana P. Parras, Dennis Kemp, Colin L. Freeman, Roger A. De Souza
Summary: In this study, molecular dynamics simulations were used to calculate oxygen diffusion coefficients in CaTiO3 with different crystal structures, revealing higher activation enthalpy for oxygen diffusion in the orthorhombic structure compared to the cubic structure. The presence of acceptor-type cation defects was found to negatively impact oxygen diffusion, especially in low-symmetry structures. The results provide insights into experimental transport studies, trends for alkaline-earth perovskites, and highlight the advantages of using MD simulations for studying ion migration in distorted perovskite structures.
JOURNAL OF MATERIALS CHEMISTRY A
(2022)
Article
Physics, Applied
A. Ardenghi, O. Bierwagen, A. Falkenstein, G. Hoffmann, J. Laehnemann, M. Martin, P. Mazzolini
Summary: The issues related to oxidation in controlling Si doping in oxide molecular beam epitaxy (MBE) were addressed by substituting solid suboxide SiO as an alternative source material. The SiO molecules were found to sublime with an activation energy of 3.3 eV. Si-doped β-Ga2O3 layers were successfully grown using this source, demonstrating unprecedented control over Si doping concentration. However, the presence of activated oxygen resulted in partial source oxidation and a decrease in doping concentration.
APPLIED PHYSICS LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Nadja Ahr, Manfred Martin
Summary: The possibility of resistive switching in perovskite-type oxides using the Hebb-Wagner polarization setup is investigated. Numerical simulations and experiments demonstrate that the Hebb-Wagner setup enables bulk resistive switching of perovskite-type oxides without the need for initially high voltages. The effect of other parameters on the switching behavior is also determined.
ADVANCED ENGINEERING MATERIALS
(2023)
Article
Engineering, Environmental
Luis Angel Castillo, Patricio J. Valades-Pelayo, Hugo J. Avila-Paredes, Juan J. Cabello, Argelia Balbuena
Summary: The distribution of light within photobioreactors is important for the photosynthetic activity of microalgae. This paper introduces a methodology for estimating the spectral radiative transport properties of microalgae cultures using measurements of incoming, transmitted, and dispersed energies. The methodology shows acceptable accuracy in estimating the spectral radiative transport properties of Chlorella vulgaris and has the potential for real-time analysis of light transport phenomena in photobioreactors.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Joe Kler, Jacqueline M. Borgers, Roger A. De Souza
Summary: The effect of surface orientation on oxygen surface exchange coefficient and surface space-charge potential in single-crystal SrTiO3 is studied. The results show that surface orientation has a significant influence on these properties.
ADVANCED MATERIALS INTERFACES
(2023)
Article
Materials Science, Multidisciplinary
Sylvia Koerfer, Alexander Bonkowski, Joe Kler, Peter Hatton, Blas Pedro Uberuaga, Roger A. De Souza
Summary: In this study, cation diffusion in fluorite-structured CeO2 is investigated using classical molecular dynamics and metadynamics simulations. It is found that cation diffusion primarily occurs through cation divacancies, rather than isolated vacancies or cation vacancy-oxygen vacancy associates.
ADVANCED ENGINEERING MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Adrian L. Usler, Dennis Kemp, Alexander Bonkowski, Roger A. De Souza
Summary: Analysis of the mean squared displacement of species k as a function of simulation time allows the extraction of tracer diffusion coefficient from a molecular dynamics simulation. The statistical error in the diffusion coefficient is often underestimated. In this study, we examined the statistics of displacement curves generated by solid-state diffusion and derived a closed-form expression for the relative uncertainty in the diffusion coefficient.
JOURNAL OF COMPUTATIONAL CHEMISTRY
(2023)
Article
Chemistry, Physical
Roger De Souza, George Harrington
Summary: The study of point defects in non-metallic crystals is important for various materials applications. Consistent definitions and terminology are necessary for progress in this field. This Comment clarifies the definitions of point defects, advocates for the correct use of relative charge in their description, and emphasizes their recognition as quasiparticles.
Article
Chemistry, Physical
Alexander Bonkowski, Caitlin Perkampus, Roger A. De Souza
Summary: By molecular dynamics simulations, we predict that substituting Ba with Ca yields a material, Ca0.5Sr0.5Co0.8Fe0.2O3-delta, that exhibits similarly high oxygen-vacancy diffusivity in its cubic form.
JOURNAL OF MATERIALS CHEMISTRY A
(2023)
Article
Chemistry, Multidisciplinary
Christiane Ader, Jakyu Chun, Han-Ill Yoo, Manfred Martin
Summary: The kinetic unmixing and decomposition of multinary oxides ABO(3) were investigated by treating it as a truly ternary system with defects in all three sublattices and electronic defects. The complete set of transport equations was derived and a numerical solution was obtained to investigate the time-dependence of kinetic unmixing. The results provide predictions for the lifetime of the oxide and the voltage threshold for kinetic decomposition.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Physical
Roger A. De Souza, Dennis Kemp, Matthew J. Wolf, Amr H. H. Ramadan
Summary: The activation energies of defect migration in ABX3 perovskite halides obtained through static supercell calculations may be unreliable at temperatures relevant to device operation due to local structural modifications. A robust test method is proposed to determine the reliability of static supercell calculations in point defect processes in perovskite systems.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Green & Sustainable Science & Technology
Fabian M. Draber, Johannes R. Denninger, Peter C. Mueller, Isabel K. Sommerfeld, Manfred Martin
Summary: This study investigates the oxygen ion conductivity of yttrium-doped BaZrO3 using density functional theory and kinetic Monte Carlo simulations. The results show that nanoscale percolation pathways are not beneficial for oxygen ion conduction due to the blocking of their motion.
ADVANCED ENERGY AND SUSTAINABILITY RESEARCH
(2022)
Article
Chemistry, Physical
Dennis Kemp, Albert Tarancon, Roger A. De Souza
Summary: In this study, we used MD and MMC simulations to determine the oxide-ion mobility in Ce1-yGdyO2-y/2 materials and proposed an analytical model to interpret the results. The findings suggest that higher oxide-ion conductivity can be achieved through non-equilibrium deposition and nanoscale-thick samples.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
