Article
Materials Science, Ceramics
Michael J. Brova, Beecher H. Watson, Rebecca L. Walton, Elizabeth Kupp, Mark A. Fanton, Richard J. Meyer, Gary L. Messing
Summary: This study investigates the effects of composition and residual template particles on the electromechanical properties of CuO-doped PYN-PMN-PT ceramics, showing that textured compositions exhibit improved properties but must be sufficiently on the rhombohedral side of the morphotropic phase boundary.
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
(2021)
Article
Chemistry, Physical
Jun Xiong, Jiayu Li, Chao Chen, Wei Jiang, Wenshuai Zhu, Huaming Li, Jun Di
Summary: This study proposes a universal strategy to engineer grain boundaries into oxides via a facile two-step growth method, and applies grain boundaries to catalytic oxidative desulfurization reactions. Taking W18O49 nanowires as an example, the engineered grain boundaries can establish stronger interfacial molecular interactions with DBT, improving surface adsorption and activation performance, as well as enhancing molecular oxygen activation capacity.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2022)
Article
Materials Science, Ceramics
Ryutaro Usukawa, Toshihiro Ishikawa
Summary: Si-Al-C-O materials are recognized as a good precursor for obtaining dense and heat-resistant SiC polycrystalline materials. The aluminum in SiC crystals plays a crucial role in creating a stable grain boundary at high temperatures, while most of the aluminum disappears during heat treatment, resulting in a dense SiC solid solution with uniformly distributed residual aluminum.
INTERNATIONAL JOURNAL OF APPLIED CERAMIC TECHNOLOGY
(2021)
Article
Chemistry, Physical
Xiang Xi, D. D. L. Chung
Summary: In graphite, the interaction between carrier atoms that causes electric polarization occurs at grain boundaries, with the electric permittivity being linearly related to the reciprocal of grain size. Smaller grain size increases permittivity by increasing the fraction of carriers participating in polarization. The interaction at grain boundaries is the main factor determining the permittivity and participation of carriers.
Review
Materials Science, Ceramics
Hidehiro Yoshida
Summary: This paper briefly summarizes recent research on high-temperature mass transport phenomena through grain boundaries in oxide ceramics. Two techniques for controlling grain boundary mass transport in oxide ceramics have been proposed: changing the chemical composition in the grain boundary, and applying an external electric field or current to the material. The former technique improves the sinterability and high-temperature plastic deformability of oxide ceramics through grain boundary segregation of doped cations. The latter technique significantly enhances diffusional mass transport through grain boundaries, and an athermal effect, in addition to the Joule heating effect, seems to exist.
JOURNAL OF THE CERAMIC SOCIETY OF JAPAN
(2022)
Article
Crystallography
Helver Augusto Giraldo-Daza, Jose Dario Agudelo-Giraldo, Cesar Leandro Londono-Calderon, Henry Reyes-Pineda
Summary: In this study, the structural defects and thermal conductivity of CuO, ZnO, and CuO/ZnO nanowires were investigated using molecular dynamics simulation. The results showed the appearance of defects after simulation, with the formation of grains to reduce energy. The CuO nanowires exhibited a contraction effect on the basal plane, while the ZnO nanowires exhibited a contraction effect on the Zn-Zn distance and the length of the nanowires.
Review
Chemistry, Multidisciplinary
Maolin Yu, Zhili Hu, Jingzhuo Zhou, Yang Lu, Wanlin Guo, Zhuhua Zhang
Summary: This review article summarizes recent advances in studying the formation mechanism, atomic structures, and functional properties of grain boundaries (GBs) in 2D materials. A complete understanding of the rich GB morphologies, their dependence on lattice misorientations and chemical compositions, is presented by analyzing the growth mechanism and the competition between far-field strain and local chemical energies of dislocation cores. The mechanical, electronic, and chemical properties tied to GBs in different materials are discussed, along with the concept of using GBs as a robust atomic-scale scaffold for realizing tailored functionalities such as magnetism, luminescence, and catalysis. Future opportunities in retrieving GBs for making functional devices and the major challenges in the controlled formation of GB structures for designed applications are also commented.
Article
Nanoscience & Nanotechnology
Megan J. McCarthy, Timothy J. Rupert
Summary: This study investigates the migration behavior of a faceted Sigma 11 boundary in Cu doped with Ag atoms, revealing that solute atoms segregate to a facet with more free volume and greatly reduce boundary velocity in one migration direction. However, a directionally-dependent motion mechanism can escape solute pinning and speed up migration in the other direction, uncovering a new mechanism of chemically-induced anisotropy in grain boundary mobility.
SCRIPTA MATERIALIA
(2021)
Article
Materials Science, Ceramics
Yan Xiong, Junwei Li, Fansi Luo
Summary: The abnormal grain growth (AGG) behavior was observed during the solid-state sintering of nano-sized BaTiO3 powder. The results challenged traditional sintering theories and proposed an explanation based on the oriented attachment of smaller grains.
CERAMICS INTERNATIONAL
(2022)
Article
Physics, Applied
Martin Kosicek, Oleg Baranov, Janez Zavasnik, Uros Cvelbar
Summary: In this study, we investigate the temperature limitations for the growth of copper oxide nanowires through thermal oxidation of copper, which has been a long-standing puzzle for scientists. By gradually lowering the oxidation temperature and using electron microscopy techniques, we determine the lowest temperature at which nanowire growth is observed and the smallest nanowire diameter achievable. Our experimental results are supported by theoretical modeling, providing insights into the nucleation processes of nanowires. The temperature dependence of the critical nucleus size governs the limiting diameter of the nanowires.
APPLIED PHYSICS LETTERS
(2023)
Review
Materials Science, Multidisciplinary
Balakrishna Palanki
Summary: The sintering of uranium dioxide, influenced by various factors, may lead to desintering and defects if not carefully controlled during manufacturing. The presence of agglomerates in the UO2 powder can be a source of defects, and these need to be managed to achieve high-density large grain sized and defect free sintered UO2 bodies. Researchers have proposed a unified explanation of the mechanisms involved in sintering, emphasizing the importance of controlling additives and atmosphere for successful sintering.
JOURNAL OF NUCLEAR MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
Ayush Suhane, Matthias Militzer
Summary: Conventional grain growth models lack consideration for the variability in grain boundary properties, and instead rely on empirical parameters. This study presents a systematic analysis that accounts for anisotropic grain boundary properties and provides a relationship to determine representative properties for an arbitrary distribution. Phase field simulations are used to analyze the effect of anisotropic mobility and segregation on average grain size evolution. It is found that the average grain size evolution can be determined using representative properties determined from simulations with varying anisotropic properties. The range of applicability for the phenomenological model is identified as moderate anisotropies.
COMPUTATIONAL MATERIALS SCIENCE
(2023)
Article
Nanoscience & Nanotechnology
Gabriel Kerbart, Christelle Harnois, Sylvain Marinel, Charles Maniere
Summary: This paper investigates the sintering characteristics of MgAl2O4 spinel using Olevsky's model to simulate the sintering trajectories. Densification and grain growth behaviors were identified through ramping and interrupted isothermal cycles, highlighting changes in final stage sintering mechanisms. The sintering trajectory model is proposed as a powerful numerical tool for sintering optimizations.
SCRIPTA MATERIALIA
(2021)
Article
Materials Science, Multidisciplinary
Yang Zuo, Cong Zhao, Ana Robador, Martin Wickham, Samjid H. Mannan
Summary: This study investigates the mechanisms of grain growth and twin formation in the bulk sintered Cu nanoparticle structure using a quasi-in-situ method. It is found that the grains continuously grow and become oriented during elevated temperature, and porosity has a greater impact on joint strength than grain or pore size. The high porosity interface between the sintered structure and the Cu substrate is eliminated due to subsequent grain boundary movement. This study provides the first detailed experimental observation of nanoscale grain growth, twin formation, and grain boundary movement in the sintered Cu structure, offering new guidance for strengthening Cu interconnections in power electronics.
Article
Chemistry, Multidisciplinary
Junli Liu, Mingxin Wang, Maria C. Dipalo, Jing Zhuang, Wenxiong Shi, Xun Wang
Summary: The study successfully prepared CuO-PMA-Ag sub-1 nm nanosheet heterostructures with excellent catalytic activity, paving the way for the synthesis and broader applications of multi-component 2D hybrid sub-1 nm heterostructures.
