Article
Materials Science, Multidisciplinary
Chang-Hua Yu, Kun-An Chiu, Thi-Hien Do, Li Chang, Wei-Chun Chen
Summary: Plasma nitridation of an amorphous SiO2 layer on Si (110) substrate can produce well-aligned alpha-Si3N4 crystallites in fibrous morphology, with a dense and straight array along Si<110>. The formed alpha-Si3N4 microfibers have a length over 2 mm with a diameter in the range of 5-10 μm, and are mainly oriented along <1120>.
Article
Nanoscience & Nanotechnology
Leilei Zhang, Yue Zhang, Feiyan Zhu, Zejun Zhao, Yong Yang, Hongchao Sheng, Xianghui Hou, Hejun Li
Summary: This study introduces a novel interlocking enhancement strategy by incorporating silicon carbide nanowires and silicon nitride nanobelts into carbon fiber composites to improve their mechanical and frictional properties. The interlocking enhancement mechanism not only increases the interlaminar shear strength and compressive strength of the composites, but also decreases the friction coefficient and wear rate.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Materials Science, Ceramics
Awais Qadir, Haroune Rachid Ben Zine, Peter Pinke, Jan Dusza
Summary: The study prepared silicon nitride ceramics containing in-situ grown Si2N2O through hot isostatic pressing at 1500 and 1700 degrees C in a nitrogen gas environment. In the tribological study, materials sintered at 1700 degrees C showed a decrease in friction coefficient with increasing sliding distance, with the system sintered with unoxidized alpha-Si3N4 powder at 1700 degrees C having the lowest COF value.
CERAMICS INTERNATIONAL
(2021)
Article
Physics, Applied
Li Yin, Kai Zhao, Zhihong Ma, Rongzheng Fan, Zhen He, Saifang Huang
Summary: Alpha-Si3N4 nanowires were successfully synthesized by a simple chemical vapor deposition method using Si and SiO2 as raw materials without the addition of metal catalyst. The reaction temperature was found to play a crucial role in determining the phase composition and morphologies of the nanowires.
INTERNATIONAL JOURNAL OF MODERN PHYSICS B
(2022)
Article
Chemistry, Physical
Chenhong Ma, Yong Li, Peng Jiang, Xi Yue
Summary: An indirect nitridation mechanism was utilized to achieve a high conversion rate of α-Si3N4 whiskers in reaction bonded Si3N4-SiC composite through the VS mechanism. The effects of temperature-time program and ultra-fine Si powder addition on the formation of SiO vapor and resulting Si3N4 whiskers were studied and clarified through experimental results and thermodynamic calculations. The results showed that the controllable indirect nitridation mechanism led to the formation of massive α-Si3N4 whiskers.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Materials Science, Ceramics
Liang Wang, Gang He, Zengchao Yang, Hongwei Zhao, Jing Zhao, Jiangtao Li
Summary: By in-situ coating SiO2, the formation of silicon monoxide (SiO) gas phase was enhanced, successfully regulating the nitridation reaction path of silicon, resulting in increased yield and purity of alpha-Si3N4.
CERAMICS INTERNATIONAL
(2021)
Article
Chemistry, Multidisciplinary
Kwan Yin Cheung, Kosuke Watanabe, Yasutomo Segawa, Kenichiro Itami
Summary: The synthesis, isolation and structural characterization of a zigzag CNB have been reported, using an iterative Diels-Alder reaction sequence and reductive aromatization method. The compound was isolated as a stable compound and its structure was fully characterized by X-ray crystallography, revealing wide energy gap and blue fluorescence properties through photophysical measurements. This research provides a synthetic strategy for all three types of CNB, paving the way for the precise synthesis of CNTs.
Article
Engineering, Chemical
Xinglong Zheng, Guixuan Wu, Dmitry Sergeev, Li Wang
Summary: This study investigates the formation process and reaction kinetics of α/β-Si3N4, revealing a multi-stage nitridation process for silicon powder involving complex phenomena like evaporation, melting, and freezing.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2022)
Article
Materials Science, Multidisciplinary
A. E. Davis, J. Donoghue, J. R. Kennedy, N. Byres, P. B. Prangnell
Summary: In-situ cooling experiments were conducted on Ti64 samples for the first time, revealing the development of alpha colonies. Primary alpha laths play a crucial role in influencing subsequent colony growth and transformation process by nucleating secondary alpha laths through sympathetic autocatalysis.
Article
Engineering, Environmental
Yixin Li, Yuemeng Ji, Jiayun Zhao, Yuan Wang, Qiuju Shi, Jianfei Peng, Yuying Wang, Chunyu Wang, Fang Zhang, Yuxuan Wang, John H. Seinfeld, Renyi Zhang
Summary: Experimental results show that the oligomerization of small alpha-dicarbonyls on sub-micrometer aerosols leads to the formation of secondary organic aerosol (SOA) and brown carbon (BrC) more efficiently upon exposure to atmospherically relevant concentrations. Carbenium ion-mediated nucleophilic addition, interfacial electric field-induced attraction, and synergetic oligomerization involving organic/inorganic species are identified as the key mechanisms for the distinct aerosol growth and light absorption in the presence of methylglyoxal.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2021)
Article
Materials Science, Ceramics
Kazuyuki Kohama
Summary: The research showed that by using different contents of Mg in Si-Mg fillers, Si3N4/Si3N4 joints with different strengths can be achieved. When the Mg content exceeds 37%, the densification/thinning of the Si layer will enhance the tensile strength of the joint, and network-like structures of MgO can be observed in high Mg content situations.
CERAMICS INTERNATIONAL
(2021)
Article
Biophysics
Hyunil Ryu, Ahmed Fuwad, Sun Min Kim, Tae-Joon Jeon
Summary: Researchers have developed a novel layered film to facilitate lipid bilayer formation with reduced formation time and increased lifetime, making it suitable for ion channel studies and biosensing purposes.
COLLOIDS AND SURFACES B-BIOINTERFACES
(2021)
Article
Chemistry, Physical
Alejandro Barrios, Cody Kunka, John Nogan, Khalid Hattar, Brad L. Boyce
Summary: This work presents a new methodology for high-throughput fatigue testing of thin films at the microscale, utilizing a microelectromechanical systems-based Si carrier to simultaneously and independently test an array of samples. The microscale fatigue behavior of nanocrystalline Al is efficiently characterized through automated fatigue testing with in situ scanning electron microscopy, reducing the total testing time significantly and revealing the stochastic nature of the microscale fatigue response. The manuscript also discusses the potential adaptations of this methodology for different samples, materials, geometries, and loading modes.
Article
Chemistry, Physical
Long Huang, Zhichao Sun, Jing Cao, Zhikun Yin
Summary: This study investigated the precipitation mechanism of secondary alpha-phase and the formation of a bimodal microstructure in Ti6242S alloy cooled from the alpha + beta phase field. It was found that both grain boundary alpha and intragranular alpha were influenced by various factors, and two types of nucleation and growth modes coexisted. The formation of several microtextured areas in the bimodal microstructure was attributed to the preferential nucleation and growth of a special alpha variant, confirming the role of Burgers orientation relationship and self-accommodation.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Chemistry, Multidisciplinary
Jiayu Alexander Liu, Jiaqi Wang, Elahe Cheraghi, Siyuan Chen, Yonghai Sun, John T. W. Yeow
Summary: In this paper, two methods for improving the field emission performance of carbon nanotube emitters are presented and compared. The treatments with dimethyl sulfoxide (DMSO) solution and poly(3,4-ethylene dioxythiophene):polystyrene sulfonate (PEDOT:PSS) solution both reduced the threshold electric field and improved the efficiency and lifetime of the CNT emitters. However, the treatment with PEDOT:PSS solution showed more significant improvements. The study demonstrates that these simple treatment methods greatly enhance the lifetime of field emission and make them suitable for large currents and long-term use.
Article
Physics, Applied
Wei Yi, Jun Chen, Seiji Higuchi, Takashi Sekiguchi
APPLIED PHYSICS EXPRESS
(2019)
Article
Physics, Applied
Jun Chen, Wei Yi, Takashi Kimura, Shinya Takashima, Masaharu Edo, Takashi Sekiguchi
APPLIED PHYSICS EXPRESS
(2019)
Article
Instruments & Instrumentation
Kazuhiro Kumagai, Akira Kurokawa
Article
Physics, Applied
Wei Yi, Jun Uzuhashi, Jun Chen, Takashi Kimura, Satoshi Kamiyama, Tetsuya Takeuchi, Tadakatsu Ohkubo, Takashi Sekiguchi, Kazuhiro Hono
APPLIED PHYSICS EXPRESS
(2019)
Article
Physics, Applied
Peng Wang, Wei Yi, Jun Chen, Shun Ito, Can Cui, Takashi Sekiguchi
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2019)
Article
Engineering, Electrical & Electronic
Jun Chen, Wei Yi, Ashutosh Kumar, Akio Iwanade, Ryo Tanaka, Shinya Takashima, Masaharu Edo, Shun Ito, Takashi Kimura, Tadakatsu Ohkubo, Takashi Sekiguchi
JOURNAL OF ELECTRONIC MATERIALS
(2020)
Article
Physics, Applied
Wei Yi, Ashutosh Kumar, Jun Uzuhashi, Takashi Kimura, Ryo Tanaka, Shinya Takashima, Masaharu Edo, Yongzhao Yao, Yukari Ishikawa, Jun Chen, Tadakatsu Ohkubo, Takashi Sekiguchi, Kazuhiro Hono
APPLIED PHYSICS LETTERS
(2020)
Article
Microscopy
Kazuhiro Kumagai, Akira Kurokawa
Article
Physics, Applied
Ashutosh Kumar, Wei Yi, Jun Uzuhashi, Tadakatsu Ohkubo, Jun Chen, Takashi Sekiguchi, Ryo Tanaka, Shinya Takashima, Masaharu Edo, Kazuhiro Hono
JOURNAL OF APPLIED PHYSICS
(2020)
Article
Crystallography
Wei Yi, Jun Chen, Takashi Sekiguchi
Article
Biochemistry & Molecular Biology
Yu-ki Tanaka, Shohei Takada, Kazuhiro Kumagai, Keita Kobayashi, Akiko Hokura, Yasumitsu Ogra
JOURNAL OF TRACE ELEMENTS IN MEDICINE AND BIOLOGY
(2020)
Article
Multidisciplinary Sciences
Yaxin Chen, Daiming Tang, Zhiwei Huang, Xi Liu, Jun Chen, Takashi Sekiguchi, Weiye Qu, Junxiao Chen, Dongrun Xu, Yoshio Bando, Xiaolei Hu, Xiaoping Wang, Dmitri Golberg, Xingfu Tang
Summary: The study successfully fabricated stable atomic silver wires (ASWs) with excellent conductivity and stability, which could be applied in thermal electrical devices.
NATURE COMMUNICATIONS
(2021)
Article
Materials Science, Multidisciplinary
Jun Chen, Wei Yi, Shun Ito, Takashi Sekiguchi
Summary: The extended defects in m-plane seed-grown GaN substrate, specifically the presence of basal-plane stacking faults (BSFs), have been studied using cathodoluminescence (CL) and transmission electron microscopy (TEM). The luminescence characteristics and emission peaks of I-1 and I-2 BSFs have been identified through high-resolution CL and spatially resolved spectral analysis. Additionally, the movement of dislocations under electron beam irradiation and its correlation with stacking faults have been discussed.
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
(2021)
Article
Physics, Applied
Ashutosh Kumar, Wei Yi, Tadakatsu Ohkubo, Jun Chen, Takashi Sekiguchi, Ryo Tanaka, Shinya Takashima, Masaharu Edo, Kazuhiro Hono
Summary: We investigated the impact of high-temperature Mg-implantation on the distribution of Mg-enriched defects in GaN layers. By using scanning transmission electron microscopy and atom probe tomography, we observed fewer Mg-enriched defects in the sample implanted at 1000℃ compared to the sample implanted at room temperature. The implantation of Mg ions at 1000℃ resulted in more uniform and enhanced donor-acceptor pair emission, leading to higher Mg activation.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Microscopy
Toshihide Agemura, Takashi Sekiguchi
