Article
Physics, Applied
S. Wu, T. L. Jin, F. N. Tan, C. C. I. Ang, H. Y. Poh, G. J. Lim, W. S. Lew
Summary: This work reports the enhancement of damping-like field and spin-orbit torque (SOT) efficiency in perpendicularly magnetized Pt/Co/HfOx heterostructures. The improvement is attributed to interfacial oxidization of the Co layer, which can be controlled by voltage-induced oxygen ion migration at the Co/HfOx interface. The enhancement and modulation of SOT by oxidation effects have potential for energy-efficient spintronic devices.
APPLIED PHYSICS LETTERS
(2023)
Article
Physics, Applied
T. Strusch, K. Lenz, R. Meckenstock, R. Bali, J. Ehrler, J. Lindner, J. Fassbender, M. Farle, K. Potzger, A. Semisalova
Summary: In this study, we investigate the spin pumping efficiency and determine the spin mixing conductance and spin diffusion length in thin bilayer films based on 3d transition metal alloy Fe60Al40. We demonstrate that the Fe60Al40 alloy exhibits dual functionality in spin pumping structures, which may have potential value in spintronic applications.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
S. N. Zhevnenko, I. S. Petrov, D. Scheiber, V. Razumovskiy
Summary: The surface energy of Ag + 0.5 at.% Fe alloy was directly measured, and segregation energy calculations in silver-based systems with iron, cobalt, and nickel were carried out. It was found that alloying silver with Ni, Co, and Fe increased the surface energy, with a stronger effect at lower temperatures. Experimental observations and DFT calculations both showed a strong anti-segregation behavior of Ni, Co, and Fe in Ag surfaces, indicating the fundamental reversibility of the Gibbs adsorption equation.
Article
Nanoscience & Nanotechnology
Ippei Suzuki, Shoichi Kubo, Hosein Sepehri-Amin, Yukiko K. Takahashi
Summary: Epitaxial thin films of L1(0)-ordered FePt alloys are crucial in magnetic recording and spintronics applications due to their large perpendicular magnetic anisotropy. This study demonstrates the importance of controlling growth mode in achieving superior properties, and highlights the role of surface free energy in tuning the growth mode to enhance PMA and surface flatness in FePt films on MgO substrates.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Chemistry, Physical
Souvik Paul, Stefan Heinze
Summary: This study demonstrates that the stability of magnetic skyrmions in an ultrathin transition-metal film can be controlled via external electric fields, and reveals the influence of electric-field-induced changes in interactions on the energy barriers for skyrmion writing and deleting.
NPJ COMPUTATIONAL MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Min-Soo Kim, Min-Ji Shin, Akshay Kumar, Kavita Kumari, Seok-Hwan Huh, Bon-Heun Koo
Summary: In this study, Ni wires were exposed to external magnetic fields of different geometrical shapes during synthesis, leading to changes in wire morphology and magnetic properties. The external magnetic field was found to have a significant impact on the morphology and magnetic anisotropy of the Ni wires.
APPLIED SCIENCES-BASEL
(2021)
Article
Materials Science, Multidisciplinary
Jiajun Lu, Weidong Liu, Yonghua Zhao
Summary: This study investigates the influence of the processing method of bulk material on the surface microstructure of the resultant workpiece in electrochemical jet texturing (EJT). The experimental results reveal evident anisotropic behavior of the texture and demonstrate the considerable influence of the rolling process on EJT.
MATERIALS & DESIGN
(2022)
Article
Chemistry, Physical
Thomas Schwab, Eva Muchova, Korbinian Aicher, Thomas Berger, Milan Oncak, Oliver Diwald
Summary: Adsorbed oxygen radicals with characteristic UV-vis spectroscopic fingerprints can be produced by compacting dehydroxylated MgO nanocrystal powders. The presence of these oxygen radicals is confirmed by photophysical calculations and electron paramagnetic resonance spectroscopy. Upon reaction with interfacial water, the oxygen radicals are converted into diamagnetic products with no absorptions in the UV-vis range. The UV-vis spectroscopic detection of transient oxygen radicals inside metal oxide powders enables in situ monitoring, which is important in various fields such as heterogeneous catalysis and sensing.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Nanoscience & Nanotechnology
Lei Shi, Lei Shangguan, Sen Yang, Yilong Zhou, Binjie Wang, Jun Xie, Yufeng Yang, Longbing He, Xiaoping Liao, Litao Sun
Summary: This study investigates the influence of surface conditions on the structure, phase, and properties of PbBi binary nanoparticles. Different surface conditions result in distinct evolution scenarios, providing direct evidence for the role of surfaces in determining structure and phase evolutions in nanoalloys. This research contributes to the understanding of the stability of binary nanoparticles in applications such as catalysis.
ACS APPLIED NANO MATERIALS
(2022)
Article
Nanoscience & Nanotechnology
Vidya Alman, Anil Annadi, Chandrasekhar Murapaka, Jhantu Pradhan, Arabinda Haldar, Vidyadhar Singh, Murtaza Bohra
Summary: Alloying antiferromagnetic Cr with ferromagnetic Ni enables the design of materials for room temperature applications with adjustable Curie temperature and magnetic interactions. This study investigates the relationship between film thickness, Cr surface segregation, and magnetic properties in nanocrystalline Ni100-xCrx thin films. The results show that the magnetic transitions and domain structure are influenced by Cr segregation evolution and film thickness. The behavior of the nanocrystalline Ni100-xCrx thin films can be adjusted by controlling the Cr doping level, providing a means for diverse magnetic applications.
ACS APPLIED NANO MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Ran Sui, Jinghuan Chang, Qiaoli Lin
Summary: This study investigates the influence of surface orientation on the reactive wetting of sapphire by Al-Ti alloys. Different atomic termination surfaces of sapphire substrates were examined, with R face exhibiting the best wetting behavior and M face showing the poorest. The addition of Ti does not result in the formation of a continuous reaction layer but contributes to the reaction process.
MATERIALS CHEMISTRY AND PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
David Jacob, Ricardo Ortiz, Joaquin Fernandez-Rossier
Summary: The study focuses on spin excitations and the Kondo effect in open-shell nanographenes, considering the impact of hybridization with a conducting substrate. The results show that the coupling to the substrate leads to significant renormalization of spin flip excitation energies, broadening of spectral features, and the emergence of zero bias Kondo peaks for the S = 1 ground states. The calculated substrate-induced shift of spin excitation energies is found to be larger than their broadening, emphasizing the importance of considering this effect when comparing experimental results and theory.
Review
Chemistry, Physical
Yanan Liu, Zhao Zhang, Zongmei Li, Xiaocui Wei, Fu Zhao, Chunyang Fan, Zhongyi Jiang
Summary: As a highly promising approach, membrane technology has gained increasing attention in various fields due to its high energy efficiency and eco-friendliness. Surface segregation, a versatile membrane fabrication method, has been developed using diverse surface segregation agents. This review highlights the recent breakthroughs in surface segregation methods and their applications in membrane fabrication, and emphasizes the strategies for regulating the physical and chemical microenvironments of membrane and pore surfaces through surface segregation.
Article
Materials Science, Multidisciplinary
Songyou Lian, Man Man Zhou, Yi Yan, Jacobus J. Terblans, Hendrik C. Swart, Jiangyong Wang, Congkang Xu
Summary: This study investigates the equilibrium surface and interface segregations in Ni(111)2 at%(Au) nano-films under diffusion-induced stress and intrinsic stress, taking into account the size effect, interlayer interactions, and heteroepitaxial strain. The equilibrium layer concentration with the lowest Gibbs free energy is determined using the coordinate descent method, and the quantitative influences of various factors on segregation in the film are evaluated.
JOURNAL OF MATERIALS SCIENCE
(2021)
Article
Chemistry, Physical
Bingbing Qiu, Yi Yang, Shuangshuang Xue, Kang Zhu, Lenan Wang, Nai Shi, Xueyu Hu, Changrong Xia, Ranran Peng, Haoliang Huang, Yalin Lu
Summary: This study investigates the effects of Sr segregation on the catalytic activity of La0.6Sr0.4Co0.2Fe0.8O3 surfaces towards oxygen surface exchange reaction, using theoretical and experimental methods. It is found that SrCO3 has positive effects on LSCF(100) and (111) surfaces, while negative effects on LSCF(110) surface. The reaction energy barriers are changed accordingly. The improved oxygen exchange kinetics on LSCF (100) and (111) surfaces are attributed to downward band bending caused by SrCO3, leading to electron accumulation.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Physical
Zhenyu Liu, Raymundo Ordonez Olivares, Yinkai Lei, Calixto Isaac Garcia, Guofeng Wang
JOURNAL OF ALLOYS AND COMPOUNDS
(2016)
Article
Physics, Applied
Corinne Gray, Yinkai Lei, Guofeng Wang
JOURNAL OF APPLIED PHYSICS
(2016)
Article
Chemistry, Physical
Yinkai Lei, Tian-Le Cheng, You-Hai Wen
JOURNAL OF POWER SOURCES
(2017)
Article
Electrochemistry
Y. Lei, T. -L. Cheng, Y. H. Wen
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
(2017)
Article
Chemistry, Physical
Lianfeng Zou, Chaoming Yang, Yinkai Lei, Dmitri Zakharov, Jorg M. K. Wiezorek, Dong Su, Qiyue Yin, Jonathan Li, Zhenyu Liu, Eric A. Stach, Judith C. Yang, Liang Qi, Guofeng Wang, Guangwen Zhou
Article
Materials Science, Multidisciplinary
Lianfeng Zou, Wissam A. Saidi, Yinkai Lei, Zhenyu Liu, Jonathan Li, Liang Li, Qing Zhu, Dmitri Zakharov, Eric A. Stach, Judith C. Yang, Guofeng Wang, Guangwen Zhou
Article
Chemistry, Physical
Tim Hsu, William K. Epting, Rubayyat Mahbub, Noel T. Nuhfer, Sudip Bhattacharya, Yinkai Lei, Herbert M. Miller, Paul R. Ohodnicki, Kirk R. Gerdes, Harry W. Abernathy, Gregory A. Hackett, Anthony D. Rollett, Marc De Graef, Shawn Litster, Paul A. Salvador
JOURNAL OF POWER SOURCES
(2018)
Article
Chemistry, Physical
Yinkai Lei, Tian-Le Chen, David S. Mebane, You-Hai Wen
JOURNAL OF POWER SOURCES
(2019)
Article
Chemistry, Physical
Yinkai Lei, Tian-Le Cheng, Harry Abernathy, William Epting, Thomas Kalapos, Gregory Hackett, Youhai Wen
Summary: The study found that under strictly humid conditions, while the presence of steam gradient leads to nickel redistribution, the formation and diffusion of Ni(OH)(2) do not significantly change the nickel coarsening rate. It is concluded that other competing mechanisms must be responsible for the observed nickel redistribution and enhanced coarsening under humid conditions.
JOURNAL OF POWER SOURCES
(2021)
Article
Chemistry, Physical
Yinkai Lei, Yueh-Lin Lee, William K. Epting, Jerry H. Mason, Tian-Le Cheng, Harry Abernathy, Gregory Hackett, You -Hai Wen
Summary: Ni redistribution in the hydrogen electrodes of solid oxide cells is an important degradation mechanism. This study investigates the interplay between Ni(OH)2 diffusion and Ni-YSZ wettability change, and identifies the driving force of Ni spreading/detachment and the factors affecting Ni redistribution. Two missing pieces in current theory of Ni redistribution are also identified.
JOURNAL OF POWER SOURCES
(2022)
Article
Chemistry, Physical
Fei Xue, Yinkai Lei, Tian -Le Cheng, William K. Epting, Gregory Hackett, Harry Abernathy, You -Hai Wen
Summary: In this study, a phase-field fracture model is developed to investigate crack growth in solid oxide cells (SOCs). The simulation results show that work-zone cracking dominates under thermal cycling in electrolyte-supported SOCs, while only minor mechanical degradation occurs in hydrogen-electrode-supported SOCs. Under redox cycling, through-cracking of yttria-stabilized zirconia (YSZ) in the hydrogen electrode and electrolyte layers dominates. Crack-mitigation strategies, such as reducing the porosity in the hydrogen electrode support layer and synchronizing thermal strain, are suggested.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Chemistry, Physical
Tian-Le Cheng, Yinkai Lei, Yun Chen, Yueying Fan, Harry Abernathy, Xueyan Song, You-Hai Wen
Summary: This study investigates the mechanism of nickel migration in nickel/yttrium-stabilized zirconia (Ni/YSZ) cermet electrodes through a combination of experimental and theoretical analysis. The results show that NiO is present at the Ni-YSZ interfaces in the active layer of both fuel cells and electrolyzer cells, despite the low nominal oxygen partial pressure at the hydrogen electrode. The volume expansion during Ni oxidation and the outward diffusion nature of NiO growth lead to nickel relocation. Thermodynamic analysis indicates that the oxygen partial pressure near the Ni-electrolyte interface can be higher than at the hydrogen electrode under polarization, promoting Ni oxidation and concentration increase of gaseous Ni(OH)2, thereby facilitating nickel transport. Therefore, a new hypothesis is proposed, suggesting the crucial role of interfacial oxidation of nickel in solid oxide cells.
JOURNAL OF POWER SOURCES
(2023)
Article
Electrochemistry
Tao Yang, Jian Liu, Yinkai Lei, Wenyuan Li, Tian-Le Cheng, Harry Finklea, You-Hai Wen, Xingbo Liu, Harry W. Abernathy, Shiwoo Lee, Thomas L. Kalapos, Gregory A. Hackett
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
(2019)
Proceedings Paper
Electrochemistry
Y. Lei, T. -L. Cheng, Y. -H. Wen
SOLID OXIDE FUEL CELLS 15 (SOFC-XV)
(2017)
