Article
Engineering, Electrical & Electronic
Kanako Shojiki, Kenjiro Uesugi, Shiyu Xiao, Hideto Miyake
Summary: III-nitride semiconductors have crystallographic polarity, and this study successfully controlled the polarity of an AlN semiconductor using a combination of sputter deposition and oxygen impurity control. By utilizing a double sputtering and annealing method, the researchers achieved vertical polarity heterostructures with controllable layer thickness without increasing the threading dislocation densities.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2023)
Article
Physics, Condensed Matter
Naoya Mokutani, Momoko Deura, Shinichiro Mouri, Kanako Shojiki, Shiyu Xiao, Hideto Miyake, Tsutomu Araki
Summary: Researchers have successfully fabricated GaN/AlN superlattices consisting of few-monolayer GaN wells with flat and abrupt interfaces by precise growth control. The superlattice structures are grown on face-to-face-annealed sputter-deposited AlN template substrates using radio-frequency plasma-excited molecular beam epitaxy (RF-MBE) and in situ reflection high-energy electron diffraction (RHEED) monitoring. AlN and GaN are grown under metal-rich conditions, and droplets are eliminated by the droplet elimination by radical beam irradiation (DERI) method for AlN and by growth interruption for GaN. The dependence of AlN thickness on superlattice properties is investigated, and it is found that the AlN thickness is easily controllable. A total of 20-period GaN/AlN superlattices with flat and abrupt interfaces is confirmed using atomic force microscopy and X-ray diffraction. Cathodoluminescence measurements show a peak wavelength of 230-260 nm at room temperature, which shifts with increasing AlN thickness.
PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Lingling Sun, Jitao Li, Jiajia Han, Maosheng Liu, Ming Meng, Binghui Li, Mingming Jiang
Summary: A workable scheme to construct high-monochromatic ultraviolet electroluminescence devices using low-dimensional ZnO micro/nanocrystals and optimized heterojunction interface has been reported in this study.
RESULTS IN PHYSICS
(2023)
Article
Chemistry, Analytical
Wenkai Yue, Ruixuan Liu, Peixian Li, Xiaowei Zhou, Yang Liu, Bo Yang, Yingxiao Liu, Xiaowei Wang
Summary: This paper investigates the effect of high-temperature annealing on the X-ray diffraction full width at half the maximum (XRD FWHM) of a 3.5 mu m-thick hydride vapor phase epitaxy-aluminum nitride (HVPE-AlN) (002) face. Tensile strain in the HVPE-AlN samples is gradually released with increasing annealing temperature. An aluminum oxynitride (AlON) region is generated at the contact interface between HVPE-AlN and sapphire when the annealing temperature exceeds 1700 degrees C, and the AlON structure conforms to the characteristics of Al5O6N.
Article
Engineering, Electrical & Electronic
Ruchi Singh, Ritesh Bhardwaj, Gaurav Siddharth, Pawan Kumar, Shaibal Mukherjee
Summary: The study demonstrates that in ZnO-based homojunction p-i-n UV photodetectors, increasing the thickness of the top p-type layer leads to a decrease in peak responsivity, while increasing the thickness of the i-ZnO layer results in an increase in responsivity. Additionally, replacing the p-type layer material can significantly improve responsivity and dark current performance.
IEEE SENSORS JOURNAL
(2021)
Article
Nanoscience & Nanotechnology
Vladimir N. Popok, Manohar Chirumamilla, Tobias Krekeler, Martin Ritter, Kjeld Pedersen
Summary: Piezoelectric AlN nanostructures with bud-like shape consisting of individual pillars/lamellae are fabricated using reactive magnetron sputter deposition technique. These nanostructures exhibit a wurtzite-like hexagonal lattice with preferential growth direction along the c-axis. Piezoresponse force microscopy characterization reveals giant values of the piezoresponse coefficient, up to 6 times higher than AlN bulk and thin films. The results provide a basis for optimizing fabrication parameters, tuning AlN piezoelectric properties, and developing energy generation technology with large-area nanoscale matrices.
ACS APPLIED NANO MATERIALS
(2023)
Article
Physics, Multidisciplinary
Di-Di Li, Jing-Jing Chen, Xu-Jun Su, Jun Huang, Mu-Tong Niu, Jin-Tong Xu, Ke Xu
Summary: AlN films were grown on sputter-deposited and annealed AlN buffer layer by high temperature hydride vapor phase epitaxy (HVPE). The crystalline quality of the AlN film could be optimized when the growth V/III ratio was 150.
Article
Materials Science, Multidisciplinary
Armin Dadgar, Florian Hoerich, Ralf Borgmann, Juergen Blaesing, Gordon Schmidt, Peter Veit, Juergen Christen, Andre Strittmatter
Summary: Sputter epitaxy is a low-cost process suitable for the deposition of high-quality group-III-nitride semiconductors, such as AlN, AlGaN, and GaN, on large substrate areas at lower growth temperatures. By using an ammonia-based reactive sputtering process in a high-purity environment, AlN can be grown with high crystalline quality and low surface roughness. Co-sputtering of Al and Ga allows for the growth of AlGaN in the entire compositional range. Thin undoped buffer layer samples exhibit high breakdown field strengths and can be used for field effect transistor (FET) buffer layers.
PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE
(2023)
Article
Physics, Applied
Kenjiro Uesugi, Shigeyuki Kuboya, Kanako Shojiki, Shiyu Xiao, Takao Nakamura, Masataka Kubo, Hideto Miyake
Summary: In this study, we optimized the sputter-deposition conditions for AlN and MOVPE growth conditions for AlGaN to reduce hillock density and size. After achieving surface-flattening of AlGaN, UV-C LEDs with a wavelength of 263 nm were fabricated on FFA Sp-AlN, and maximum external quantum efficiencies of approximately 4.9% and 8.0% were achieved without and with silicone encapsulation, respectively.
APPLIED PHYSICS EXPRESS
(2022)
Article
Materials Science, Ceramics
Chang Liu, Mingli Qin, Haoyang Wu, Zhirui Zhang, Yiming Zhang, Yuelong Wang, Baorui Jia, Dengshuai Guo, Xuanhui Qu
Summary: In this paper, an estimation method was presented to reveal the relationship between residual oxygen content and Y2O3 additive amount used in AlN sintering. It was found that the AlN sample added with 3 wt% Y2O3 showed better performance than the others when the oxygen content was 0.765 wt% in the initial powders. However, short-time sintering did not result in ultra-high performance as estimated. By employing two-step sintering regimes, the distribution of the second phase in the AlN ceramic was significantly changed, leading to improved bending strength and decreased residual oxygen content.
CERAMICS INTERNATIONAL
(2023)
Article
Nanoscience & Nanotechnology
Haidi Wu, Jing Ning, Jincheng Zhang, Yu Zeng, Yanqing Jia, Jianglin Zhao, Ling Bai, Yanbo Wang, Shiyu Li, Dong Wang, Yue Hao
Summary: By combining graphene and sputtered AlN as the nucleation layer, a high-quality and low-dislocation AlN epitaxial layer was successfully obtained on a C-sapphire substrate via metal organic chemical vapor deposition. A 277 nm AlGaN-based deep ultraviolet light emitting diode (DUV-LED) was fabricated based on the obtained AlN epitaxial layer. The presence of graphene promotes stress release in AlN and the nucleation layer facilitates annihilation of threading dislocations in AlN. As a result, the screw dislocation density of the AlN epitaxial layer significantly decreased from 2.31 x 10(9) to 2.08 x 10(8) cm(-2). A high-performance DUV-LED with a forward turn on voltage of 3.5 V at room temperature was achieved using the high-quality AlN films. This study provides a meaningful strategy for obtaining high-quality AlN films and high-performance DUV-LEDs.
Article
Chemistry, Multidisciplinary
Xiaojuan Sun, Jiaen Sui, Jianwei Ben, Hang Zang, Ke Jiang, Shanli Zhang, Shunpeng Lv, Zhiming Shi, Tong Wu, Dabing Li
Summary: This study investigates the underlying mechanism of the decrease in basal stacking fault density in a nonpolar AlN template. It is found that the elimination of the I-1-type stacking fault involves its transformation into an I-3-type stacking fault, followed by annihilation. The results presented here are significant for the synthesis of high-quality nonpolar AlN materials and nonpolar light-emitting diodes.
Article
Chemistry, Analytical
Yong Ruan, Yang Chen, Yu Wu, Meng Shi, Yan Du, Zhiqiang Song, Yiyang Chen, Helei Dong, Congchun Zhang, Jiao Teng
Summary: A Pt/Ti/AlN/Mo/AlN/Si structure surface acoustic wave (SAW) temperature sensor was prepared, and the high temperature characteristics were measured at 20-600 degrees C under different electrode metallization rates (eta). It was observed that frequent device mutation occurred in the first high-temperature test, and the mutation point decreased as the electrode metallization rate (eta) increased. Subsequent tests showed stable data, increased center frequency, decreased return loss (S11), and increased factor of merit (Q). Annealing the sensors at 600 degrees C for 30 min resulted in improved performance in the first test, indicating that proper annealing can enhance sensor performance. Furthermore, the annealed SAW sensor was tested in the temperature range of 20-1000 degrees C, meeting the requirement of a temperature range of 20-900 degrees C, with a linear f-T curve, a factor of merit (Q) of 34.5, and a sensitivity of 46.6 KHz/K.
Review
Physics, Applied
Kenjiro Uesugi, Hideto Miyake
Summary: This paper discusses the application potential of low-TDD FFA Sp-AlN templates in deep-ultraviolet light-emitting devices, and reviews recent progress in reducing threading dislocation density (TDD) and epitaxial growth of AlN and Al x Ga1-x N on FFA Sp-AlN. The achieved TDD on sapphire substrates with a 1.2 μm AlN film thickness was approximately 4 x 10(7) cm(-2). Additionally, the performance of DUV light-emitting diodes fabricated on FFA Sp-AlN is demonstrated, indicating the promising prospects of this approach.
JAPANESE JOURNAL OF APPLIED PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
Sebastian Walde, Cheng-Yao Huang, Chia-Lung Tsai, Wen-Hsuang Hsieh, Yi-Keng Fu, Sylvia Hagedorn, Hung-Wei Yen, Tien-Chang Lu, Markus Weyers, Chia-Yen Huang
Summary: The research successfully prepared high-power and high-quality UVC LED by engineering the lattice constants and dislocation densities of various layers in AlGaN-based UVC LEDs, providing an effective strategy for the preparation of corresponding devices.
Article
Nanoscience & Nanotechnology
Jianxing Xu, Xiaodong Tong, Shiyong Zhang, Zhe Cheng, Lian Zhang, Penghui Zheng, Feng-Xiang Chen, Rong Wang, Yun Zhang, Wei Tan
Article
Chemistry, Physical
Lian Zhang, Rong Wang, Zhe Liu, Zhe Cheng, Xiaodong Tong, Jianxing Xu, Shiyong Zhang, Yun Zhang, Fengxiang Chen
Summary: This study investigated the regulation of hole concentration and mobility in p-InGaN layers grown under an N-rich environment. By adjusting the growth temperature, the hole concentration can be controlled, meeting different device requirements. First-principles defect calculations suggested that Mg-i mainly compensated for the holes in p-type InGaN grown in an N-rich environment.
Article
Chemistry, Analytical
Li-Fang Jia, Lian Zhang, Jin-Ping Xiao, Zhe Cheng, De-Feng Lin, Yu-Jie Ai, Jin-Chao Zhao, Yun Zhang
Summary: In this study, AlGaN/GaN E/D-mode GaN inverters were successfully fabricated on a 150-mm Si wafer and a systematic analysis of their key electrical characteristics was conducted from room temperature to 200 degrees C. The results demonstrate the small variations of inverters at different temperatures and the great potential for GaN smart power integrated circuit (IC) application.
Article
Physics, Applied
Lian Zhang, Zhe Cheng, Yawei He, Jianxing Xu, Lifang Jia, Xinyuan Wang, Shiyong Zhang, Wei Tan, Yun Zhang
Summary: This study focuses on the electron concentration and mobility of SAG n(+)-GaN on InAlN/GaN HEMTs using MOCVD, revealing that the electron mobility of SAG GaN is significantly affected by thickness. A gas flow model is proposed to guide the regrowth for improving electron mobility. High mobility and low resistance are achieved in the SAG GaN, contributing to the performance of the HEMTs.
APPLIED PHYSICS LETTERS
(2021)
Article
Engineering, Electrical & Electronic
Lian Zhang, Xinyuan Wang, Jianping Zeng, Lifang Jia, Zhe Cheng, Yujie Ai, Zhe Liu, Wei Tan, Yun Zhang
Summary: This paper reports on the high-performance N-p-n AlGaN/GaN heterojunction bipolar transistors (HBTs) on sapphire substrates, which exhibit high current gain, low ON-resistance, and high current density. The performance of the devices at high temperatures is also evaluated.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Article
Engineering, Electrical & Electronic
Ranran Wang, Lifang Jia, Xingfa Gao, Jiaheng He, Zhe Cheng, Zhe Liu, Lian Zhang, Yun Zhang
Summary: This study demonstrates the high-temperature operation of AlGaN/GaN high electron mobility transistors (HEMTs) and direct-coupled FET logic (DCFL) inverters, NOR gates, and NAND gates. The p-GaN-gate HEMTs used in DCFL circuits exhibit proper E-mode operation with stable threshold voltage and high electron mobility at 300 degrees C. The fabricated logic gates have a small switching time at room temperature and exhibit a slight increase in switching time at 300 degrees C, while still maintaining accurate and stable operation.
IEEE ELECTRON DEVICE LETTERS
(2023)
Article
Engineering, Electrical & Electronic
Lei Ye, Jie Yang, Jiaheng He, Hua Yang, Weiqiang Zhao, Ping Chen, Zhe Liu, Yun Zhang
Summary: This study proposes a wide-range correlated color temperature (CCT) white light laser-based illuminant consisting of dual blue laser diodes (LDs), yellow phosphor color converters, and red LDs. By manipulating the power ratio and peak wavelength of the LDs, different spectral power distributions were simulated to achieve a balance between optical performance and blue light hazard efficiency of radiation (BLHER). The fabricated practical device shows excellent color rendering index (CRI) beyond 85, high luminous flux, and high luminous efficiency of radiation (LER) at a wide CCT range.
IEEE PHOTONICS TECHNOLOGY LETTERS
(2023)
Article
Engineering, Electrical & Electronic
Yujie Ai, Hongrui Lv, Yinglong Huang, Jiaheng He, Ye Wang, Jiwen Wu, Yun Zhang
Summary: In this study, a surface acoustic wave (SAW) resonator with high quality factors (Q) of 3526/10 205 at the resonant/antiresonant frequencies (f(r)/f(a)) was successfully fabricated on thick metal-organic chemical vapor deposition (MOCVD)-grown (0002) aluminum nitride (AlN) films (4 μm) on sapphire. The investigation on device parameters, including aspect ratio of length to width (L/W), number of interdigital transducers (IDTs), and IDT metal thickness, revealed that the high Q was achieved due to the large L/W value of 12 and the thick AlN film (4 μm). Furthermore, the resonator exhibited a high Q of 4027 at 250 °C and temperature coefficient of frequency (TCF) values of -46.52/-46.09 ppm/°C for f(r)/f(a) in the temperature range from -50 °C to 250 °C, showing promising potential for temperature sensor application.
IEEE SENSORS JOURNAL
(2023)
Article
Engineering, Electrical & Electronic
Yawei He, Lian Zhang, Zhe Cheng, Chengcheng Li, Jiaheng He, Shujie Xie, Xuankun Wu, Chang Wu, Yun Zhang
Summary: This paper reports on a scaled In0.17Al0.83N/GaN high-electron-mobility transistor (HEMT) fabricated on a sapphire substrate. The device has a T-gate length of 47 nm, a source-drain distance of 300 nm, and selective area regrown n(+)-GaN. It exhibits cutoff frequencies f(T)/f(max) of 190/301 GHz and a record sqrt (f(T) x f(max)) = 239 GHz, surpassing previous Ga-polar GaN-on-sapphire HEMTs. The device demonstrates excellent current density, external direct current transconductance, I-on/I-off ratio, and other characteristics.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Nanoscience & Nanotechnology
Xingfa Gao, Jie Yang, Jiaheng He, Bingyue Cui, Lian Zhang, Zhe Liu, Yujie Ai, Defeng Lin, Mingtong Wu, Yun Zhang
Summary: This study demonstrates the successful realization of n-AlGaN free deep-ultraviolet light-emitting diode (DUV-LED) with transverse electron injection by selective area regrowth (SAG) n(+)-GaN for the first time. The transverse structure LEDs, which have multiple quantum wells (MQWs) and upper layers directly deposited on the AlN template, exhibit lower threading dislocation density and better surface morphology compared to conventional structure LEDs with thick n-AlGaN layer. The transverse structure LEDs also show significantly improved internal quantum efficiency, electroluminescence intensity, and emission characteristics.
Article
Materials Science, Multidisciplinary
Rong Wang, Jianxing Xu, Shiyong Zhang, Ying Zhang, Penghui Zheng, Zhe Cheng, Lian Zhang, Feng-Xiang Chen, Xiaodong Tong, Yun Zhang, Wei Tan
Summary: Low-fluence neutron irradiation is a promising way to reduce the reverse leakage current in AlGaN/GaN heterostructures while maintaining other electronic properties almost unchanged. The mechanism involves the mobility of neutron scattered group-III interstitials, passivation of V-III-DLs, and escape of interstitials after saturation of passivation. This post-processing treatment offers a new approach for improving the electronic properties of AlGaN/GaN heterostructures grown by MOCVD on sapphire substrates.
JOURNAL OF MATERIALS CHEMISTRY C
(2021)
Article
Engineering, Electrical & Electronic
Ruxue Ni, Zhiguo Yu, Zhe Liu, Lian Zhang, Lifang Jia, Yun Zhang
IEEE PHOTONICS TECHNOLOGY LETTERS
(2020)
Article
Chemistry, Physical
J. Zamora, T. Bautista, N. S. Portillo-Velez, A. Reyes-Montero, H. Pfeiffer, F. Sanchez-Ochoa, H. A. Lara-Garcia
Summary: Experimental and DFT studies were conducted on the structural, magnetic, and optical properties of RFeO3 perovskites. The perovskites exhibited an orthorhombic crystal structure and weak ferromagnetic behavior. They were confirmed to be semiconductors with a bandgap of approximately 2.1 eV.
JOURNAL OF ALLOYS AND COMPOUNDS
(2024)
Article
Chemistry, Physical
Xianxiang Lv, Jing Jin, Weiguang Yang
Summary: By depositing TiN and TiO2 surface layers on AlSi films, the electrochemical performance of silicon-based anodes can be significantly improved, suppressing volume expansion and promoting the formation of a stable SEI layer.
JOURNAL OF ALLOYS AND COMPOUNDS
(2024)
Article
Chemistry, Physical
Sharafat Ali, Haider Ali, Syedul Hasnain Bakhtiar, Sajjad Ali, Muhammad Zahid, Ahmed Ismail, Pir Muhammad Ismail, Amir Zada, Imran Khan, Huahai Shen, Rizwan Ullah, Habib Khan, Mohamed Bououdina, Xiaoqiang Wu, Fazal Raziq, Liang Qiao
Summary: The construction and optimization of redox-heterojunctions using a bifunctional phosphate as an electron-bridge demonstrated significant improvements in photo catalytic activity, including enhanced dispersion, reduced interfacial migration resistance, and increased abundance of active-sites.
JOURNAL OF ALLOYS AND COMPOUNDS
(2024)
Article
Chemistry, Physical
Ren-Ni Luan, Na Xu, Chao-Ran Li, Zhi-Jie Zhang, Yu-Sheng Zhang, Jun Nan, Shu-Tao Wang, Yong-Ming Chai, Bin Dong
Summary: Extensive research has revealed that oxygen evolution reaction (OER) in alkaline conditions involves dynamic surface restructuring. The development and design of sulfide/oxide pre-catalysts can reasonably adjust the composition and structure after surface reconstruction, which is crucial for OER. This study utilized a simple two-step hydrothermal method to achieve in situ S leaching and doping, inducing the composition change and structure reconstruction of CoFe oxides. The transformed FeOOH and CoOOH exhibited excellent OER activity and could be easily mass-produced using low-cost iron based materials and simple methods.
JOURNAL OF ALLOYS AND COMPOUNDS
(2024)
Article
Chemistry, Physical
Jun'an Lai, Daofu Wu, Peng He, Kang An, Yijia Wang, Peng Feng, WeiWei Chen, Zixian Wang, Linfeng Guo, Xiaosheng Tang
Summary: Zero-dimensional organic-inorganic metal halides (OMHs) are gaining attention in the fabrication of light-emitting diodes due to their broad emission band and high photoluminescence quantum yield. This work synthesized a zero-dimensional organic tetraphenylphosphonium bismuth chloride (TBC) that showed efficient blue light emission, with the emission mechanism attributed to the transition of Bi3+ ions. White light-emitting diodes (WLEDs) were fabricated using TBC, along with green-emitting and red-emitting single crystals, achieving single-component white emissions. These findings demonstrate the different emission mechanism of ns2 ions-based OMHs and highlight the potential of bismuth-based OMHs in WLEDs applications.
JOURNAL OF ALLOYS AND COMPOUNDS
(2024)
Article
Chemistry, Physical
Xuewei Liang, Yunhai Su, Taisen Yang, Zhiyong Dai, Yingdi Wang, Xingping Yong
Summary: The revolutionary design concept of high-entropy alloys has brought new opportunities and challenges to the development of advanced metal materials. In this work, AlCrCuFe2NiTix high-entropy flux cored wires were prepared by combining the design idea of a high-entropy alloy with the characteristics of flux cored wire. AlCr-CuFe2NiTix high-entropy surfacing alloys were prepared using gas metal arc welding technology. The wear properties of the alloys were analyzed, and the phase composition, microstructure, strengthening mechanism, and wear mechanism were discussed. The results show that the alloys exhibit a dendritic microstructure with BCC/B2 + FCC phases. Increasing Ti content leads to the precipitation of Laves phase. The alloys show improved microhardness and wear resistance due to the precipitation of coherent B2 and Laves phases. However, excessive Ti addition results in the increase of Laves phase and reduced wear resistance of the alloys.
JOURNAL OF ALLOYS AND COMPOUNDS
(2024)
Article
Chemistry, Physical
M. Vadivel, M. Senthil Pandian, P. Ramasamy, Qiang Jing, Bo Liu
Summary: This work presents the enhanced photocatalytic and electrochemical performance of g-C3N4 assisted PAA on CoFe2O4 ternary nanocomposites. The incorporation of PAA and g-C3N4 improves the separation efficiency of photogenerated charge carriers, resulting in superior photocatalytic degradation and high specific capacitance values.
JOURNAL OF ALLOYS AND COMPOUNDS
(2024)
Article
Chemistry, Physical
Vibhu T. Sivanandan, Ramany Revathy, Arun S. Prasad
Summary: In this study, pure and doped cobalt ferrite nanoparticles were prepared using the sol-gel auto-combustion method with the aid of lemon juice as eco-fuel. The crystal structure, lattice parameter, crystallite size, microstrain, optical parameters, and room temperature magnetic properties of the samples were analyzed. The effect of doping on the magnetic properties was also investigated.
JOURNAL OF ALLOYS AND COMPOUNDS
(2024)
Article
Chemistry, Physical
Qing Guo, Bowen Zhang, Benzhe Sun, Yang Qi
Summary: This study prepared ZnO films with various nonpolar preferred orientations using conventional chemical bath deposition method and characterized their growth process and mechanism. It was found that the type and concentration of nitrate could control the preferred orientation and surface roughness of ZnO films. Additionally, ZnO films with different preferred orientations exhibited different optical properties.
JOURNAL OF ALLOYS AND COMPOUNDS
(2024)
Article
Chemistry, Physical
Chong Zhang, Yan Liu, Zhaoyan Wang, Hang Yang
Summary: In this study, six bimetallic FeCo particles were synthesized via the hydrothermal method at different Fe:Co ratios. The Fe:Co ratio not only modulates the composition of the particles but also influences their structure and magnetic properties. The FeCo alloys showed a transformation from an Fe-based structure to a Co-based structure with increasing Co content. The Fe:Co ratio of 1:1 and 3:1 resulted in particles with the highest and lowest saturation magnetization, respectively.
JOURNAL OF ALLOYS AND COMPOUNDS
(2024)
Article
Chemistry, Physical
Jianning Zhang, Jing Li, Yiren Wang, Xiaodong Mao, Yong Jiang
Summary: We conducted a study on the formation of ultra-fine Y-Ti-Ta-O nano-oxides in Ta+B micro-alloyed 13CrWTi-ODS alloys using electron microscopy and first-principles calculations. The Y-Ti-Ta-O nano-oxides were found to be mainly Y2(Ti,Ta)2O7, with an average size of 7 nm and a number density of 6.8 x 1023 m-3. Excess boron was found to enhance the adhesion of some low-sigma grain boundaries but weaken the Fe/Y2Ti2O7 interface, while excess tantalum enhanced the Fe/Y2Ti2O7 interface but caused serious degradation of grain boundaries.
JOURNAL OF ALLOYS AND COMPOUNDS
(2024)
Article
Chemistry, Physical
Yirong Fang, Pei Cheng, Hang Yuan, Hao Zhao, Lishu Zhang
Summary: A new composite system of nitrogen-doped reduced graphene oxide and black phosphorus quantum dots has been developed for tumor therapy, showing improved electrochemical properties and stability. The system generates hydrogen peroxide and hydroxyl radical to effectively kill tumor cells.
JOURNAL OF ALLOYS AND COMPOUNDS
(2024)
Article
Chemistry, Physical
Xiufang Qin, Yuanli Ma, Hui Zhang, Ting Zhang, Fang Wang, Xiaohong Xu
Summary: The structure and magnetism of cobalt ferrites after Mn2+-Tb3+ co-doping were studied. Co-doped samples exhibited cubic spinel structure and spherical shape of ferrite nanoparticles. The redistribution of Co2+ and Fe3+ ions between octahedral and tetrahedral sites was observed due to Mn2+-Tb3+ co-doping. The coercivity and magnetization saturation of co-doped samples were significantly improved, leading to a maximum energy product that is 190% higher than that of the un-doped sample.
JOURNAL OF ALLOYS AND COMPOUNDS
(2024)
Article
Chemistry, Physical
Ho Yeon Lee, Wonjong Yu, Yoon Ho Lee
Summary: Recently, there has been an increasing interest in developing ultra-fine nanostructured electrodes with extensive reaction areas to enhance the performance and low-temperature operation of solid oxide fuel cells. The use of a refined approach involving co-sputtering metal alloys and oxide targets has demonstrated the feasibility of nano-columnar structures in perovskite-based electrodes, expanding the temperature range of thin film electrodes. This study systematically examines the effects of chamber pressure control in the co-sputtering process and identifies the intricate relationship between sputtering pressure and film structure. By fine-tuning the columnar growth in the electrode, significant improvements in performance and thermo-mechanical properties were achieved, resulting in high-performance all-sputtered solid oxide fuel cells.
JOURNAL OF ALLOYS AND COMPOUNDS
(2024)
Article
Chemistry, Physical
Qianyun Bai, Xiaoxiao Yan, Da Liu, Kang Xiang, Xin Tu, Yanhui Guo, Renbing Wu
Summary: This study proposes a simple method to develop a non-precious transition metal-based electrocatalyst with high catalytic activity and robustness for the hydrogen evolution reaction. The as-synthesized electrode exhibits a low overpotential and high current density, indicating its potential in energy conversion.
JOURNAL OF ALLOYS AND COMPOUNDS
(2024)
