Article
Materials Science, Ceramics
Gerson J. J. Leonel, Xin Guo, Gurpreet Singh, Christel Gervais, Alexandra Navrotsky
Summary: This study investigates the thermodynamic stability of SiC(O) and SCN(O) ceramics derived from different polymeric precursors. The results show that the microstructure of the polymer-derived ceramics (PDCs) differs depending on the precursor used. The addition of nitrogen contributes to the thermodynamic stabilization of PDCs, particularly in the case of SiCN(O) structures.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2023)
Article
Materials Science, Ceramics
Mariano Hernan Talou, Javier Oswaldo Bolanos Rivera, Maria Andrea Camerucci
Summary: Porous Si/C/O/(N) ceramic bodies were prepared by direct consolidation of liquid silicon-based preceramic polymer/porogen systems followed by burnout and N2 pyrolysis. The material was characterized by porosity analysis, phase evolution study, and microstructure analysis. The ceramics exhibited hierarchical porosity with larger irregular pores and a smaller volume of meso- and micropores. The presence of meso- and micropores contributed to the high specific surface area achieved in the material pyrolyzed at 1500 degrees C.
CERAMICS INTERNATIONAL
(2023)
Article
Polymer Science
Jun Wang, Matthias Gruenbacher, Simon Penner, Maged F. Bekheet, Aleksander Gurlo
Summary: In this study, a Pd-containing precursor was synthesized from palladium acetate and poly(vinyl)silazane, and Pd nanoparticles were in-situ formed during the pyrolysis of the precursor. The pyrolyzed nanocomposites exhibited good catalytic activity towards the dry reforming of methane, with the sample pyrolyzed at 700 degrees C showing the best performance attributed to the in situ formed Pd nanoparticles and high BET surface area.
Article
Materials Science, Ceramics
Rahul Anand, Kathy Lu, Bibhuti B. Nayak, Shantanu K. Behera
Summary: Polymer-derived SiCN materials can be tailored with Hf incorporation to achieve improved phase stability and oxidation resistance. The doping of a molecular precursor in the preceramic polymer led to the formation of a unique glass-ceramic nanocomposite of t-HfO2-SiCN. The resulting material exhibited a single amorphous phase up to 900°C and crystallization of t-HfO2 occurred at higher temperatures.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2023)
Article
Materials Science, Ceramics
He Wu, Kewei Wang, Baisheng Ma, Ke Ren, Yiguang Wang
Summary: The isothermal evolution of free carbon structure and conductivity of polycarbosilane-derived SiC(O) ceramics pyrolyzed at different temperatures was systematically investigated. The results showed that the structure and ordering degree of free carbon changed with annealing time, and the conductivity of the samples was enhanced.
CERAMICS INTERNATIONAL
(2023)
Article
Chemistry, Physical
Ivan Hung, Emanuel Ionescu, Jishnu Sen, Zhehong Gan, Sabyasachi Sen
Summary: The atomic structure of an amorphous silicon oxycarbide polymer-derived ceramic with Si-O-C tetrahedral network was studied using 1D and 2D Si-29 NMR techniques. The study found that the Si-O-C network consists of SiO4, SiO3C, SiO2C2, and SiC4 units, with significant chemical shift anisotropy observed for the SiOxC4-x units. Additionally, the SiC4 units showed significant clustering at the interface between the Si-O-C network and carbon nanodomains.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Chemistry, Physical
Yuxuan Liao, Sotaro Iwamoto, Michiko Sasaki, Masahiro Goto, Junichiro Shiomi
Summary: Advanced means of reducing the thermal conductivity of dense amorphous materials through nanostructuring is crucial for thermal management in future electronic and optical devices. By measuring the thermal conductivity of amorphous-silicon/amorphous-silica superlattices, it was shown that nanostructures can inhibit the transport of diffusons in addition to scattering propagons, allowing for significant tunability of amorphous thermal conductivity using truly nanoscale structures. The effects of interface scattering on diffusion transport can be effectively described by the Boltzmann transport equation, revealing the similarities between propagons and diffusons.
Article
Materials Science, Ceramics
Jiongjie Liu, Emmanuel Ricohermoso, Wei Li, Xingmin Liu, Zhuhui Qiao, Emanuel Ionescu, Ralf Riedel
Summary: In this study, a WC-containing SiOC glass-ceramic was synthesized via pyrolysis and SPS. The sintering behavior, phase composition, and microstructure of the ceramics were investigated. The results showed that increasing the sintering temperature enhanced the densification of the ceramics and reduced the disorder of free carbon in SiOC. Furthermore, the incorporation of WC particles effectively improved the mechanical properties of the ceramics.
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
(2022)
Article
Nanoscience & Nanotechnology
Udayan Banik, Ashutosh Agrawal, Hosni Meddeb, Oleg Sergeev, Nies Reininghaus, Maximilian Goetz-Koehler, Kai Gehrke, Jonas Stuhrenberg, Martin Vehse, Maciej Sznajder, Carsten Agert
Summary: Efficient radiative cooling to subambient temperatures has been achieved using a simple dip-coated planar polymer emitter derived from polysilazane, showing high selectivity and durability. This structure, with high transparency polymer and underlying silver mirror, reduces ambient temperature by 6.8 degrees Celsius under direct sunlight, demonstrating a cooling power of 93.7 W m(-2) and offering a new perspective for prospective passive daytime radiative cooling structures.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Materials Science, Ceramics
Nathalie Thor, Jan Bernauer, Nils-Christian Petry, Emanuel Ionescu, Ralf Riedel, Astrid Pundt, Hans -Joachim Kleebe
Summary: Ultra-high temperature ceramic nanocomposites (UHTC-NC) were synthesized in the Si(HfxTa1_x)(C)N system via the polymer-derived ceramics (PDC) synthesis route. The microstructure evolution of the materials was studied during pyrolysis and subsequent heat treatment, revealing differences in phase composition and micro-structure between bulk and surface regions. High-temperature annealing resulted in the formation of transition metal carbides (TMC) instead of nitrides due to the decomposition reaction triggered by residual carbon and diffusion-controlled coarsening.
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
(2023)
Article
Chemistry, Physical
Yin Wang, Chunjia Luo, Yaofeng Wu, Xi Hu, Liuying Wang, Xi Chen, Min Chao, Gu Liu, Yongbiao Hu, Luke Yan
Summary: In this study, amorphous monolithic siliconboron carbonitride ceramics were prepared, which exhibited outstanding microwave absorption property. By optimizing the ordered carbon structures through adjusting the crosslinking agent content and pyrolysis temperature, the microwave absorption performance was improved. Additionally, the ceramics showed excellent high temperature stability with only 3.23% mass loss in air.
Article
Chemistry, Physical
Casey Sugie, Alexandra Navrotsky, Stefan Lauterbach, Hans-Joachim Kleebe, Gabriela Mera
Summary: The study synthesized two preceramic polymers with unique organic groups, resulting in SiOC PDCs with and without mixed bonding. Raman spectra revealed the presence of carbon nanoscrolls and open edge structures in SiOC PDCs. Thermodynamic measurements showed that SiOC PDCs with mixed bonding are more stable than those without.
Article
Chemistry, Physical
M. Alejandra Mazo, Isabel Padilla, Aurora Lopez-Delgado, Aitana Tamayo, Juan Rubio
Summary: The study demonstrates that dense materials like SiOCd and SiOC-SiCd perform well in thermal shock tests by forming a protective silica layer to mitigate damage. In contrast, porous materials like SiOCNp and SiOCp failed the thermal shock tests as they resulted in large depressions.
Article
Engineering, Manufacturing
Li Wang, Ning Wang, Sen Shi, Ke Wang, Bingheng Lu
Summary: In this study, a layerless printing method is proposed to achieve straight-walled ceramic structures without layer steps. The method utilizes an oxygen inhibition layer to control the formation of steps during the printing process. The results showed that layerless printing reduced the surface roughness of the ceramic, increased its hardness and modulus, and provided more uniform stress distribution.
ADDITIVE MANUFACTURING
(2022)
Article
Materials Science, Ceramics
Qing Zhang, Fang Ye, Wenyan Duan, Laifei Cheng, Litong Zhang
Summary: The effects of heat treatment temperature and TBT content in precursor on the microstructure, phase composition, and microwave absorbing properties of TiC/SiC/SiOC ceramics were investigated. The increase of TBT content leads to higher TiC content and lower SiC content in the ceramics. Adjusting TBT content within 1 to 5 wt.% range has little effect on the real part of the dielectric constant of TiC/SiC/SiOC ceramics.
INTERNATIONAL JOURNAL OF APPLIED CERAMIC TECHNOLOGY
(2022)
Article
Materials Science, Ceramics
Zilong Xiong, Wenzhuo Xue, Mujun Li, Feihu Tan, Yupeng Chen, Hongyu Yu
Summary: In this study, CBS glass/Al2O3 composites were developed for LTCC applications based on a CaO-B2O3-SiO2 (CBS) glass system with a high boron content. The study revealed that the softening of glass and interfacial reaction between the glass and Al2O3 were the two most important factors affecting LTCC's densification process. Real-time shrinkage rate of LTCC during sintering was successfully simulated, and it was proven that the formation of the CaAl2(BO3)O phase played a significant role in reducing glass viscosity and promoting dense structure formation. The resulting LTCC composite exhibited excellent performance for high-frequency applications.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2024)
Article
Materials Science, Ceramics
Saurabh Kumar Sharma, Vinita Grover, Rakesh Shukla, Abid Hussain, Ambuj Mishra, Pawan Kumar Kulriya
Summary: In this study, the disordering caused by swift heavy ion irradiation in two different compositions of pyrochlore structures was investigated. X-ray diffraction, Raman spectroscopy, and high-resolution transmission electron microscopy were used to analyze the samples before and after irradiation. It was found that both compositions underwent amorphization due to irradiation, with a slower rate observed in Nd1.8Zr2.2O7.1. The irradiation-induced modified track region in Nd1.8Zr2.2O7.1 consisted of defect-rich pyrochlore structure, anion-deficient fluorite structure, and amorphous domains.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2024)
Article
Materials Science, Ceramics
Jiabei He, Mengshan Song, Ming Yang, Miaomiao Zhu
Summary: This study investigates the influence of ion irradiation on high-entropy ceramics and finds that irradiation-induced lattice rearrangement can improve the radiation resistance of these ceramics.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2024)
Article
Materials Science, Ceramics
Yajie Yu, Shi He, Zhengang Zhang, Haihua Chen, Peipeng Jin, Binnian Zhong, Linhui Zhang, Liping Wang, Cheng Lu
Summary: Silicide ceramics, including tantalum disilicide (TaSi2), are known for their exceptional physical properties but are limited in practical applications due to their inherent brittleness at room temperature. In this study, we successfully improved the mechanical properties of TaSi2 ceramics and increased their electrical conductivity by modifying the preparation methods and sintering conditions. These findings provide valuable insights for future applications of TaSi2 and the design of advanced ceramic materials.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2024)
Article
Materials Science, Ceramics
Jian Li, Jia Liu, Yongcui Zhang, Wei Sun, Yang Wang, Haitao Wu, Ling Li, Chuanbing Cheng, Yingying Wang, Ke Tan, Futian Liu
Summary: Microstructure design plays a crucial role in regulating the microwave dielectric properties of materials, however, the understanding of frequency temperature stability and related micromechanism remains limited. In this study, a combination of first-principles calculations and experimental observation was used to investigate the correlation among sintering behavior, crystal structure, bonding nature, and microwave dielectric properties of LnPO(4) (Ln = Eu, Pr) ceramics. The research findings systematically clarify the optimized effect and micromechanism of lanthanides on the dielectric properties of monazite ceramics, providing insights into the design and enhancement of microwave dielectric materials.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2024)
Article
Materials Science, Ceramics
Wenqian Pan, Xizhen Xia, Wei Zhou, Yang Li
Summary: The study investigates the frictional and wear behaviors of carbon fiber-reinforced SiC ceramic matrix composites with different fiber orientations mating with ceramic balls. The results show that fiber orientation significantly affects the friction and wear properties of the composites. Pads with randomly arranged fibers demonstrate better friction stability and lower wear volume, potentially suitable for bearing material applications. The research also explores the factors influencing the formation of continuous tribo-film and identifies abrasive wear and oxidation wear as the dominant wear mechanisms for the friction pairs.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2024)
Article
Materials Science, Ceramics
Sergey Nikolaevich Perevislov, Ilya Evgenievich Arlashkin, Valentina Leonidovna Stolyarova
Summary: This paper describes the synthesis and sintering of MAX phases in the Zr-Al-C system. Different mixtures of initial Zr/Al/C and Zr/Al/ZrC powders were used to synthesize Zr2AlC and Zr3AlC2 MAX phases. The highest content of Zr3AlC2 MAX phase was obtained using a component ratio of 1:1.5:2-51.1 vol.% of Zr/Al/ZrC powders.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2024)
Article
Materials Science, Ceramics
Weijia Luo, Xubin Wang, Baiheng Bai, Jianli Qiao, Xingcong Chen, Yongzheng Wen, Jingbo Sun, Lingxia Li, Ji Zhou
Summary: This study successfully establishes the relationship between internal strain and dielectric loss by synthesizing and designing specific structure of tungsten bronze ceramics, and concludes that controlling internal strain can effectively reduce dielectric loss. This research is of great significance for the development of future all-ceramic non-Hermitian devices.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2024)
Article
Materials Science, Ceramics
Santanu Mondal, Juan Diego Shiraishi Lombard, Sreenivasulu Gollapudi, Carolina Tallon, Jie-Fang Li, Dwight Viehland
Summary: Ultrafast high-temperature sintering (UHS) is an effective method for rapidly densifying ZrB2 powders. The final grain size increases with longer sintering duration. X-ray diffraction and energy-dispersive spectroscopy show crystalline phase and compositional uniformity in ZrB2 after UHS.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2024)
Article
Materials Science, Ceramics
JiaNan Wang, ZhiQiang Li, YongZheng Zhu, Yao Liang, Yan Cui, HuaLong Tao, Bo Song, Alexander Nikiforov, ZhiHua Zhang
Summary: First-principles calculations were performed to investigate the crystal structure, electronic structure, and ion diffusion of sulfur-doped Li2FeSiO4. The results showed that sulfur doping can improve the electronic conductivity and reduce the energy barrier for ion diffusion.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2024)
Article
Materials Science, Ceramics
Xiaodi Dai, Serdar Aydin, Mert Yuecel Yardimci, Gunter Reekmans, Peter Adriaensens, Geert De Schutter
Summary: This study investigates the rheological behavior, solidification process, and nanostructure changes of sodium hydroxide-activated slag (NH-AAS) and sodium silicate-activated slag (SS-AAS) pastes over time. The results show that NH-AAS and SS-AAS release similar heat and reach a similar reaction degree at their initial setting times, but have different gel structures.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2024)
Article
Materials Science, Ceramics
Yanliang Ji, Simon Becker, Zichen Lu, Alexander Mezhov, Regine von Klitzing, Schmidt Wolfram, Dietmar Stephan
Summary: This study reveals the significant influence of resting time on the rheological properties of cement suspensions, which is closely related to non-absorbed polycarboxylate superplasticizers (PCEs) size variation. Adsorbed PCE during resting tends to bridge particles instead of dispersing them, leading to an increased yield stress.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2024)
Article
Materials Science, Ceramics
Yifeng Huang, Xin Wang, Yinchang Ma, Xiang Lv, Jiagang Wu
Summary: This study investigates the effect of K/Na ratio on the phase structure, ferroelectric domains, and piezoelectric properties of potassium sodium niobate (KNN)-based ceramics. It reveals that high Na+ content leads to large ferroelectric domains, while high K+ content results in local polarity heterogeneity and distinct dielectric relaxational behavior. The balanced local polarity and stress heterogeneities contribute to improved piezoelectricity.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2024)
Article
Materials Science, Ceramics
Zun Xia, Yedong Rong, Hao Li, Ye Dong, Hongbo Yu, Jie Xu, Xiuhui Wang, Jinlong Yang
Summary: This study presents the synthesis of hollow MgAl2O4 particles in situ within porous ceramics, resulting in volume expansion and the formation of a hierarchical pore structure, leading to a significant improvement in compressive strength.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2024)
Article
Materials Science, Ceramics
Honglong Wang, Zhiguo Sun, Faming Xia, Chenguang Yang, Xiaoguang Wang, Jintang Li, Linxu Jiang
Summary: In this study, the micro-geometry morphology variation and microstructural transformation mechanism of muscovite crystals under electron beam irradiation were explored. The results revealed the instability of the muscovite lattice under irradiation, as well as the expansion and shrinkage of the lattice with increasing dose. The study also identified changes in chemical structure and other mechanisms involved. These findings are significant for the design of radiation-resistant silicate materials and the manufacturing of electronic components used in the aerospace industry.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2024)