Article
Chemistry, Physical
Yuyang Hou, Guoguang Cheng, Kota Kadoi, Hiroshige Inoue
Summary: The formation of Ti2O3-TiN originates from the Ti-O-N particle, with Ti2O3 and TiN precipitating sequentially from it to constitute Ti2O3-TiN. Subsequently, the surface of the formed Ti2O3-TiN will promote delta-ferrite nucleation, contributing to suitable compositional design for equiaxed solidification.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Crystallography
Douglas M. Matson, Xuanjiang Liu, Justin E. Rodriguez, Sangho Jeon, Olga Shuleshova
Summary: The study shows that containerless processing can monitor the double recalescence process and predict delay behavior based on the retained damage model. Fe-Cr-Ni alloys and Fe-Co alloys exhibit different properties, with an increased cluster attachment rate and reduced free energy retention.
Article
Chemistry, Physical
H. Men, Z. Fan
Summary: In this paper, prenucleation and heterogeneous nucleation in the liquid Pb/solid Al system were investigated using molecular dynamics simulation. It was found that a 2-dimensional ordered structure with a coincidence site lattice (CSL) formed at the interface, accommodating the lattice mismatch. The study also revealed that the CSL was an effective mechanism for systems with large positive misfit.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Huijun Cao, Yu Zhang, Yinggan Zhang, Jiajia Han, Dongchuan Su, Zhihao Zhang
Summary: The miniaturization trend of three-dimensional integrated circuits presents challenges to solder reliability. This study comprehensively explores the solder evolution under high current stressing, considering the anisotropic characteristics of beta-Sn. The results reveal that the anisotropy of beta-Sn aggravates the nonuniform distribution of current-induced stresses, leading to multiple migration modes in the solder bump. Additionally, electron-dislocation interaction promotes dislocation slip and lattice rotation, and current-induced grain merging via detwinning is observed. The study contributes to a better understanding of anisotropic evolution and damage mechanisms in micro solder bump design under current stressing.
MATERIALS & DESIGN
(2022)
Article
Materials Science, Multidisciplinary
Y. Cui, J. W. Xian, A. Zois, K. Marquardt, H. Yasuda, C. M. Gourlay
Summary: The factors affecting the nucleation and morphology of large Ag3Sn plates in solder joints are not well understood. This study investigates the faceted solidification of Ag3Sn and reveals transitions from single crystal plates to cyclic twinned plates and highly branched structures. Real-time X-ray imaging confirms that Ag3Sn cyclic twins originate from a common point during nucleation or the early stages of growth. Soldering to copper substrates catalyzes Ag3Sn nucleation through constitutional supercooling and geometrical catalysis.
Article
Chemistry, Physical
Y. Cui, C. M. Gourlay
Summary: The study investigates how different twin types and twin variants affect the growth morphology during solidification in primary Al45Cr7 and Al13Fe4 intermetallic compounds (IMCs). The number of twin variants increased with cooling rate, and cyclic twinning resulted in different growth morphologies depending on the twin variants present.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Chemistry, Multidisciplinary
Yongsheng Ren, Hui Chen, Wenhui Ma, Yi Zeng, Kazuki Morita
Summary: A Si-Sn alloy melt solution was used to grow large-area bulk Si, overcoming difficulties associated with high-temperature crystal transformation. Electron back-scattered diffraction and theoretical calculation were employed to identify the primary dendrite and elucidate the preferential formation of grains. Simulation was conducted to estimate the interfacial energy during directional solidification. The residual concentrations of Sn in the bulk primary Si were found to be closer to the solid solubility limit compared to impurity concentrations in Si grown from other solutions.
CRYSTAL GROWTH & DESIGN
(2022)
Article
Materials Science, Multidisciplinary
Gang Du
Summary: The morphology, growth behavior, and formation mechanism of TiC in TiC-reinforced wear-resistant steel were investigated, revealing TiC's potential as a preferred heterogeneous site for ferrite during solidification. Experimental observations were consistent with theoretical calculations, highlighting the structural relationship between TiC and ferrite.
MATERIALS SCIENCE AND TECHNOLOGY
(2021)
Article
Crystallography
Simon Recnik, Milan Bizjak, Jozef Medved, Peter Cvahte, Blaz Karpe, Ales Nagode
Summary: The study fabricated bismuth-added aluminum alloy AA6026 using different melt preparation methods, finding that the melt preparation route influenced the solidification sequence and machinability of the alloy, and explanations were provided through thermodynamic analyses and microstructural characterization.
Article
Engineering, Multidisciplinary
Haijie Zhang, Menghuai Wu, Peter Schumacher, Christian M. G. Rodrigues, Andreas Ludwig, Abdellah Kharicha
Summary: The study investigates the phenomenon of solidification and re-melting in technical castings and their impact on structural homogeneity. A new model is proposed to address both grain nucleation and destruction, aimed at improving understanding of the solidification/melting process.
APPLIED MATHEMATICAL MODELLING
(2021)
Article
Nanoscience & Nanotechnology
Yanhui Wang, Jianrong Gao, Lunhua He
Summary: Ni77Ga23 alloys were rapidly solidified and undercooled using glass fluxing treatment. The study indicates that rapid solidification leads to the formation of a disordered solid solution, and high undercoolings result in the formation of an equiaxed microstructure. Within the equiaxed grains, coherent cuboidal precipitates of Ni3Ga phase are dispersed, and HRTEM study reveals the presence of disordered nano-domains in the lattice of Ni3Ga phase.
SCRIPTA MATERIALIA
(2024)
Article
Nanoscience & Nanotechnology
Zhiqi Fan, Yu Yin, Qiyang Tan, Xuliang Li, Pengda Niu, Ruidi Li, Tiechui Yuan, Ming-Xing Zhang, Han Huang
Summary: The crystallographic texture distribution in 3D-printed Al2O3-ZrO2 eutectics is different from those prepared by directional solidification. The printed specimen consists of randomly oriented eutectic colonies, where the Al2O3 particles in the uncoupled region act as nucleation sites. Multiple crystallographic orientation relationships exist within the eutectic colonies.
SCRIPTA MATERIALIA
(2022)
Article
Chemistry, Physical
Dean Eaton, Ivan Saika-Voivod, Richard K. Bowles, Peter H. Poole
Summary: The authors tested the theoretical free energy surface (FES) for two-step nucleation (TSN) by comparing it to numerical results from Monte Carlo simulations, finding that the theory successfully predicted FES over a range of thermodynamic conditions. This demonstrates that Iwamatsu's extension of classical nucleation theory provides an excellent framework for understanding the thermodynamics of TSN.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Review
Metallurgy & Metallurgical Engineering
Guang Zeng, Shiqian Liu, Qinfen Gu, Zebang Zheng, Hideyuki Yasuda, Stuart D. McDonald, Kazuhiro Nogita
Summary: It is widely recognized that a fundamental understanding of phase transformation and microstructure control in Pb-free solder joints can accelerate the development of Pb-free solder alloys for next-generation electronics. Advanced characterization techniques, including synchrotron radiation, provide a comprehensive toolset for measuring the composition, crystallography, morphology, and properties of solder alloys. Research findings on the effects of micro-alloy additions on the microstructure and properties of Pb-free solder joints, particularly on intermetallic phases, have significant scientific and industrial implications for the design of new solder alloy compositions and the reliability of lead-free solder joints.
ACTA METALLURGICA SINICA-ENGLISH LETTERS
(2022)
Article
Engineering, Electrical & Electronic
Bismarck Luiz Silva, Pedro Henrique Mendes, Amauri Garcia, Jose Eduardo Spinelli
Summary: In addition to intermetallic growth, phase dissolution, and precipitation, the variation in dendritic scale is an important factor to consider in solder joint operations. This study explores the evolution of dendritic array, Ag3Sn spacing, and hardness in the SAC207 alloy under different aging conditions. The research finds that the initial dendritic spacing and cooling rate have a crucial impact on dendritic array coarsening, and the Ag3Sn spacing connected to spheroidal-like particles is more susceptible to coarsening.
JOURNAL OF ELECTRONIC MATERIALS
(2022)
Article
Chemistry, Physical
L. Peng, G. Zeng, C. J. Lin, C. M. Gourlay
Summary: This study investigates carbide formation during interface reactions between solid Fe-xC alloys and liquid AZ91. Two ternary carbides, AlFe3C and Al2MgC2, are formed in the reaction layers, with T2-Al2MgC2 additionally forming within the AZ91 alloy due to carbon pickup. T2-Al2MgC2 grows in liquid AZ91 as hexagonal plates that are commonly twinned, with a reproducible orientation relationship measured between T2-Al2MgC2 and alpha-Mg.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Engineering, Electrical & Electronic
A. A. Daszki, C. M. Gourlay
Summary: The study reveals that the interlaced regions in Sn-3.0Ag-0.5Cu (SAC305) solder balls can be reasonably approximated as a hollow double cone, which explains a range of partially interlaced morphologies observed in past research on 2-D cross-sections.
JOURNAL OF ELECTRONIC MATERIALS
(2021)
Article
Engineering, Electrical & Electronic
J. W. Xian, S. A. Belyakov, C. M. Gourlay
Summary: The coarsening of Ag3Sn particles occurs at 125 degrees C in the eutectic regions of Sn-3Ag-0.5Cu/Cu solder joints, with coalescence of particles playing a significant role in the ripening process. Approximately 10% of the initial Ag3Sn particles coalesced during aging, showing uniform distribution across the eutectic regions. The size distribution histograms indicated large particles best fit by the Takajo model of coalescence ripening, with similar macroscopic coarsening kinetics observed between surface and bulk Ag3Sn particles. Tracking of individual surface particles revealed an interplay between growth/shrinkage and coalescence of Ag3Sn.
JOURNAL OF ELECTRONIC MATERIALS
(2021)
Article
Chemistry, Physical
Y. Cui, C. M. Gourlay
Summary: The study investigates how different twin types and twin variants affect the growth morphology during solidification in primary Al45Cr7 and Al13Fe4 intermetallic compounds (IMCs). The number of twin variants increased with cooling rate, and cyclic twinning resulted in different growth morphologies depending on the twin variants present.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Materials Science, Multidisciplinary
Yangchao Deng, Guang Zeng, Jingwei Xian, Hongyi Zhan, Chuming Liu, Christopher M. Gourlay
Summary: In this study, the formation of intermetallic compounds during the solidification of multi-phase magnesium alloys was comprehensively investigated. The experimental results showed that Mg2Sn forms eutectic particles with 13-Mg17Al12 and r-MgAlZn, containing multiple phases. The lattice match between Mg2Sn and r-MgAlZn was found to be the best, with Mg2Sn being correlated with the icosahedral coordination in r-MgAlZn.
MATERIALS CHARACTERIZATION
(2022)
Article
Materials Science, Multidisciplinary
Liuqing Peng, Guang Zeng, Di Wang, Jingwei Xian, Shouxun Ji, Hongyi Zhan, Christopher M. Gourlay
Summary: This study investigates the formation of Al-Mn IMCs in Mg-9Al-0.7Zn-0.2Mn alloy produced by high-pressure die casting and direct chill casting. The results show that controlling solidification and filtration during casting is important for ensuring small Al-Mn intermetallic particles in these casting processes.
Article
Chemistry, Physical
L. Peng, G. Zeng, J. Xian, C. M. Gourlay
Summary: The influence of iron on the formation of Al-Mn-Fe intermetallic compounds (IMCs) has been investigated. It was found that the iron content affects the phase fractions and morphology of the IMCs.
Article
Engineering, Mechanical
Yilun Xu, Jingwei Xian, Stoyan Stoyanov, Chris Bailey, Richard J. Coyle, Christopher M. Gourlay, Fionn P. E. Dunne
Summary: This paper presents a multi-scale modelling approach to investigate the underpinning mechanisms of microstructure-sensitive damage of single crystal Sn-3Ag-0.5Cu solder joints. The crystallographic orientation and its role in fatigue damage have been studied systematically, providing optimal solder microstructural design for in-service thermomechanical fatigue.
INTERNATIONAL JOURNAL OF PLASTICITY
(2022)
Article
Nanoscience & Nanotechnology
Yilun Xu, Tianhong Gu, Jingwei Xian, Finn Giuliani, T. Ben Britton, Christopher M. Gourlay, Fionn P. E. Dunne
Summary: The mechanical properties and temperature sensitivity of beta-Sn single crystals and polycrystalline beta-Sn-rich alloys have been investigated using a combination of experimental and numerical methods. The results provide insights into the behavior of electronic solders under thermomechanical loading.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Materials Science, Multidisciplinary
N. Hou, J. W. Xian, A. Sugiyama, H. Yasuda, C. M. Gourlay
Summary: In this study, we investigated the morphology transitions of the β-Sn + Ag3Sn eutectic at increasing growth velocity. The orthorhombic Ag3Sn grew as faceted plates or rods with [010] growth direction and (001) as the largest facet in three eutectic growth morphologies. Reproducible β-Sn + Ag3Sn orientation relationships were observed in the latter two morphologies. The mechanisms of spacing adjustment and the reversible transition from plate to rod growth were studied for transient solidification after velocity changes.
METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE
(2023)
Article
Materials Science, Multidisciplinary
Y. Cui, J. W. Xian, A. Zois, K. Marquardt, H. Yasuda, C. M. Gourlay
Summary: The factors affecting the nucleation and morphology of large Ag3Sn plates in solder joints are not well understood. This study investigates the faceted solidification of Ag3Sn and reveals transitions from single crystal plates to cyclic twinned plates and highly branched structures. Real-time X-ray imaging confirms that Ag3Sn cyclic twins originate from a common point during nucleation or the early stages of growth. Soldering to copper substrates catalyzes Ag3Sn nucleation through constitutional supercooling and geometrical catalysis.
Article
Chemistry, Physical
C. J. Lin, L. Peng, J. W. Xian, Q. Li, C. M. Gourlay
Summary: In hypoeutectic Mg-Al-based alloys, Mg17Al12 forms by a eutectic reaction that is usually divorced. The nucleation, growth, and morphology of Mg17Al12-containing eutectic in a multicomponent Mg-9Al-0.7Zn-0.2Mn alloy are investigated. Mg17Al12 forms an interconnected 3D skeleton and occasionally has a preferred orientation relationship with alpha-Mg. The degree of partially divorced growth depends on geometric measures, and fully coupled eutectic microstructures can be generated by manipulating the solidification time and cooling rate.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Materials Science, Multidisciplinary
Yang Yang, Yangchao Deng, Ruifeng Zhang, Yuqing Su, Siyue Liu, Christopher M. Gourlay, Guang Zeng
Summary: This study investigates the correlation between microstructure and corrosion behavior of AZ series alloys using various techniques. The results show that a 3D interconnected eutectic network protects against localized corrosion in chloride solution. Additionally, Al-Mn intermetallics treated with a solution lead to filament corrosion instead of pitting corrosion, due to a reduction in potential difference.
Article
Nanoscience & Nanotechnology
Tim M. Schwarz, Hongyi Zhan, Baptist Gault, Christopher M. Gourlay, Ingrid McCarroll
Summary: The peak-aged magnesium-aluminum-rare earth (Mg-Al-RE) alloy AE44-2, produced through high-pressure die casting, exhibits a 10% increase in yield strength due to the formation of nanoscale AlMn precipitates. Atom probe tomography reveals the presence of Ce-rich clusters in the dendritic region rather than the inter-dendritic alpha-Mg in the as cast state, indicating their formation is mainly determined by solidification kinetics rather than concentration. These Ce-rich clusters act as heterogeneous nucleation sites for the formation of Al10Mn7RE2 nanoscale precipitates during the T5 heat treatment, suggesting a potential pathway for tailoring mechanical properties.
SCRIPTA MATERIALIA
(2023)
Article
Engineering, Electrical & Electronic
S. A. Belyakov, R. J. Coyle, B. Arfaei, J. W. Xian, C. M. Gourlay
Summary: This study investigates the impact of adding antimony to Pb-free solders on their thermal cycling performance in harsh conditions. The presence of SbSn and Ag3Sn as strengthening particles within the solder is found to significantly improve the solder's performance during accelerated thermal cycling.
JOURNAL OF ELECTRONIC MATERIALS
(2021)
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)