Article
Materials Science, Multidisciplinary
Xi Chen, Shao-Long Jiang, Dong-Wei Wang, Kang Yang, Jin-Hui Lu, Guang-Hua Yu
Summary: The effect of ultrathin Fe layer on perpendicular magnetic anisotropy (PMA) in Co/Pt multilayers was investigated. The position of the Fe layer at the interface strongly influenced the PMA. When the Fe layer was doped at the Co/Pt interface, the PMA decreased monotonically with increasing Fe layer thickness. However, when the Fe layer was doped at the Pt/Co interface, the PMA showed a peak at a specific thickness. The variation in PMA is mainly attributed to the tuning of electron occupation states at Fe-doped Pt/Co interface.
Article
Physics, Applied
D. Ourdani, Y. Roussigne, S. M. Cherif, M. S. Gabor, M. Belmeguenai
Summary: The interfacial Dzyaloshinskii-Moriya interaction and perpendicular magnetic anisotropy can be controlled through interface engineering, allowing for the manipulation of skyrmion generation and size. The correlation between the two interactions enables simultaneous control, facilitating the development of magnetic multilayers for memory and logic applications. Experimental techniques such as VSM, BLS, and MS-FMR were used to investigate the relationship between the interactions, revealing the interface anisotropy constants and the influence of Pd thickness on the interactions.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
M. Cinal
Summary: The relationship between magnetocrystalline anisotropy (MCA) energy and the anisotropy of the orbital magnetic moment (AOM) for the (001) fcc Co film and Co/X bilayers (X = Pd and Pt) were investigated using a realistic tight-binding model. The extension of the Bruno relation, including the AOM of both Co and Pd or Pt, accurately predicted the MCA energy for both bilayers without needing extra scaling. However, the extended van der Laan relation failed to reproduce the MCA energy, its sign, and the oscillation pattern accurately.
Article
Chemistry, Physical
Mikhail V. Dorokhin, Anton V. Zdoroveyshchev, Marina P. Temiryazeva, Alexei G. Temiryazev, Polina B. Demina, Olga V. Vikhrova, Alexey V. Kudrin, Irina L. Kalentyeva, Mikhail V. Ved, Anastasia N. Orlova, Vladimir N. Trushin, Alexandr V. Sadovnikov, Dmitry A. Tatarskiy
Summary: We investigated the magnetic properties and micromagnetic structure of multilayer Co/Pt films with varying bilayer thickness. Magnetic force microscopy and Lorentz transmission electron microscopy revealed the presence of Néel-type skyrmions in the films, with the density strongly dependent on the bilayer thickness parameter. The observed effects are attributed to the Dzyaloshinskii-Moriya interaction, which is influenced by the regularities of magnetic and nonmagnetic layers alternation. We highlight the controllability of the skyrmion density in this system through modulation of technological parameters.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Chemistry, Physical
M. Slezak, P. Drozdz, K. Matlak, A. Koziol-Rachwal, A. A. Sasikala Devi, M. Alatalo, T. Slezak
Summary: Gas adsorption on the surface of (Fe/Co)(N) superlattices drives the rotation of magnetization angle in Fe(110) ferromagnet. The sensitivity of spin orientation to adsorption can be controlled by terminating the surface with Co or Fe. The purely surface-limited adsorption process alters the magnetic anisotropy of the entire superlattice, making it an artificial surface.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Physics, Applied
Nicholas W. G. Smith, Yannick Pleimling, Brenden A. Magill, Rathsara R. H. H. Mudiyanselage, Alex Shenenberger, Shunta Ogawa, Nozomi Nishizawa, Hiro Munekata, Giti A. Khodaparast
Summary: In this study, we investigated the femtosecond-pulse-induced precession of magnetization in Co/Pd multilayer systems with different Co thicknesses. We found that the precession amplitudes increase as the Co layer thickness decreases. Further analysis showed that the enhancement of structural-dependent energy transfer efficiency is responsible for the observed variations in precession amplitudes.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
B. Brahma, Pratap Behera, S. Ravi, R. Brahma, S. K. Srivastava
Summary: This study prepared a series of multilayer thin films to investigate the effect of Cu insertion layer on magnetic properties, and found that the coercivity values increase with the thickness of the Cu insertion layer.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2021)
Article
Chemistry, Physical
Binbin Liu, Xiangjiang Yu, Xin Jiang, Yi Qiao, Li You, Yao Wang, Feng Ye
Summary: The surface topography, interface roughness, and phase transformation of Al/Ni multilayers are strongly dependent on the substrates, with substrate roughness significantly affecting interface roughness and phase transformation behavior. Substrates can influence the intermixing region at interfaces and may provide advantages for tailoring the performance of multilayers.
APPLIED SURFACE SCIENCE
(2021)
Article
Engineering, Electrical & Electronic
M. Caseiro, R. Macedo, P. D. R. Araujo, S. Cardoso, M. Erkovan, P. P. Freitas
Summary: The magnetic properties of Co/Pt and Co/Pd multilayers with an Ir spacer were studied. Strong interlayer exchange coupling was observed in Co/Pt-based structures, while lower coupling was found in Co/Pd multilayers. Only the former showed high post-annealing stability at 330°C, while the latter exhibited ferromagnetic coupling due to spacer deterioration. The stability of Ir-based Co/Pt p-SAF structures was confirmed by calculating Hex, which reached 370°C before losing all interlayer exchange coupling.
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2023)
Article
Engineering, Manufacturing
Fraser Daniel, Andy Gleadall, Adarsh D. Radadia
Summary: The study focuses on examining the anisotropy and impedance scaling in materials extrusion-based additive manufacturing, finding that while conductivity may change with extrusion temperature, the Z/F ratio remains constant. By investigating the scaling of impedance with interfaces, the study aims to provide a framework to model and predict electrical behavior in electric sensors and actuators.
ADDITIVE MANUFACTURING
(2021)
Article
Chemistry, Multidisciplinary
Waqar Ali Memon, Ruimin Zhou, Yajie Zhang, Yuheng Wang, Lixuan Liu, Chen Yang, Jianqi Zhang, Adeel Liaqat, Liming Xie, Zhixiang Wei
Summary: The epitaxial crystallization of thin films on highly oriented polyethylene (PE) substrates enhances the crystal orientation of small molecules and significantly improves charge transport properties. Aligned edge-on molecules show maximum mobilities that are tens of times higher than those of unaligned molecules, demonstrating a critical understanding and effective approach for achieving high-performance organic electronic applications.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Chemistry, Physical
Young Chan Won, Sang Ho Lim
Summary: The study investigates the perpendicular magnetic anisotropy and crystalline structure of Ta/NiFeB/MgO stacks. Annealing induces PMA and increases magnetic moment, with the thinnest 0.5-nm Ta layer showing the strongest PMA at 400 degrees Celsius. X-ray diffraction confirms the formation of NiFe (001) phase essential for high tunneling magnetoresistance ratio.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Chemistry, Multidisciplinary
Mengchao Li, Huali Yang, Yali Xie, Kai Huang, Lili Pan, Wei Tang, Xilai Bao, Yumeng Yang, Jie Sun, Xinming Wang, Shenglei Che, Run-Wei Li
Summary: The magnetic properties of flexible magnetic films are sensitive to mechanical stress due to magnetoelastic coupling, which affects the performance of flexible magnetoelectronic devices. We demonstrate that stacking different materials in multilayers can enhance the stress stability of the magnetic properties. The strength of magnetoelastic anisotropy and the initial effective magnetic anisotropy play significant roles in determining the stress stability of the film.
Article
Chemistry, Multidisciplinary
Houbing Zou, Hu Shi, Shijiao Hao, Yajuan Hao, Jie Yang, Xinxin Tian, Hengquan Yang
Summary: In this study, the oil-water interfaces of Pickering emulsions were utilized to regulate catalytic selectivity of hydrogenation reactions by controlling the spatial distribution of metal nanoparticles at the droplet interfaces. The remarkable interfacial microregion-dependent catalytic selectivity was found to be attributed to the microenvironments of the coexistence of water and organic solvent at the droplet interfaces, altering the adsorption patterns of the reactants on the metal nanoparticles. This strategy provides new insights into liquid-liquid interfacial reactions and offers a way to enhance catalytic selectivity.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Materials Science, Multidisciplinary
Thomas A. Schefer, David L. Cortie, Mikhail Kostylev
Summary: By using ferromagnetic resonance (FMR) spectroscopy, we have found that the FMR peak in Pd/[Co/Pd](30)/Pd multilayer thin films shifts in the presence of hydrogen gas, with a larger shift observed for samples with thicker Pd layers. We have also observed a correlation between the linewidth and the Pd layer thickness, which can be explained by the presence of spin pumping.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Etienne Bousser, Aleksey Rogov, Pavel Shashkov, Ali Gholinia, Nicolas Laugel, Thomas J. A. Slater, Philip J. Withers, Allan Matthews, Aleksey Yerokhin
Summary: This study demonstrates that the high-temperature alpha-Al2O3 phase can still be formed even if microdischarge is fully suppressed under specific processing conditions. Through the use of various techniques, the microstructural and chemical evolutions accompanying the gamma to alpha alumina transition were studied. The results provide strong evidence that the alpha phase can form spontaneously in regions of oxide with the appropriate temperature, grain size, and impurity distributions.
Article
Chemistry, Physical
Tatiana Latychevskaia, Colin Robert Woods, Yi Bo Wang, Matthew Holwill, Eric Prestat, Sara Mustafi, Sarah J. Haigh, Konstantin S. Novoselov
Summary: This study demonstrates the possibility of directly measuring scattering parameters through the intensity distribution of spots in CBED patterns. A method for recovering atomic scattering parameters from CBED patterns is proposed and validated through experiments and simulations.
Article
Chemistry, Physical
Naomi Lawes, Isla E. Gow, Louise R. Smith, Kieran J. Aggett, James S. Hayward, Lara Kabalan, Andrew J. Logsdail, Thomas J. A. Slater, Malcolm Dearg, David J. Morgan, Nicholas F. Dummer, Stuart H. Taylor, Michael Bowker, C. Richard A. Catlow, Graham J. Hutchings
Summary: Palladium-based materials have been used as catalysts for the conversion of carbon dioxide and hydrogen to methanol. Forming PdZn and PdGa alloys improves the methanol selectivity and productivity. The preferential formation of PdZn alloy over PdGa alloy in the presence of Ga2O3 may be attributed to the easier reduction of ZnO compared to Ga2O3.
FARADAY DISCUSSIONS
(2023)
Article
Chemistry, Physical
Kevin P. P. Treder, Chen Huang, Cameron G. G. Bell, Thomas J. A. Slater, Manfred E. E. Schuster, Dogan Ozkaya, Judy S. S. Kim, Angus I. I. Kirkland
Summary: We introduce nNPipe for the automated analysis of morphologically diverse catalyst materials. This method utilizes automated imaging routines and convolutional neural networks to analyze large data stacks quickly and accurately. It overcomes the limitations of traditional image analysis approaches and provides insights into real industrial catalytic samples in the context of automated imaging.
NPJ COMPUTATIONAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
William J. Cull, Stephen T. Skowron, Ruth Hayter, Craig T. Stoppiello, Graham A. Rance, Johannes Biskupek, Zakhar R. Kudrynskyi, Zakhar D. Kovalyuk, Christopher S. Allen, Thomas J. A. Slater, Ute Kaiser, Amalia Patane, Andrei N. Khlobystov
Summary: In this study, single-layer, ultrathin, subnanometer-wide indium selenides (InxSey) were synthesized using templated growth inside single-walled carbon nanotubes (SWCNTs). The phase of the encapsulated material was identified through experimental analysis and simulations, and the identities of the encapsulated species were confirmed using various analytical techniques. These materials have the potential for applications in nanoelectronic components.
Article
Chemistry, Multidisciplinary
Shouqi Shao, Gareth R. M. Tainton, W. J. Kuang, Nick Clark, Roman Gorbachev, Alexander Eggeman, Irina V. Grigorieva, Daniel J. Kelly, Sarah J. Haigh
Summary: Through the use of 4D scanning transmission electron microscopy (4DSTEM) and energy dispersive X-ray spectroscopy (EDS), it was found that there is structural and chemical heterogeneity, as well as the formation of previously unknown intermediate superstructures, during potassium intercalation and deintercalation processes. The developed in situ correlative STEM-EDS methodology has the potential to determine optimal synthesis, processing, and working conditions for various intercalated or pillared materials.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Pankaj Sharma, Monika Sharma, Malcolm Dearg, Martin Wilding, Thomas J. A. Slater, C. Richard A. Catlow
Summary: The use of Cd/Pt precursor solutions for photocatalytic H-2 production is demonstrated, achieving significant improvement in production rate and eliminating the need for pre-synthesized photocatalysts. In addition, Pt single-atoms are synthesized in situ and anchored on CdS nanoparticles, leading to enhanced active sites and suppressed charge recombination, resulting in high efficiency for solar-to-hydrogen conversion and H-2 production. This work provides a promising strategy for maximizing H-2 production efficiency and offers a green process for H-2 production and synthesis of highly photoactive Pt-SA-CdSIS nanoparticles.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Biotechnology & Applied Microbiology
Jinxin Xie, Victoria S. Coker, Brian O'Driscoll, Rongsheng Cai, Sarah J. Haigh, Jonathan R. Lloyd
Summary: This study found that Geobacter sulfurreducens cannot directly reduce pentavalent antimony or cause its release. The results highlight the close associations between iron and antimony in environmental systems, suggesting the potential use of iron for remediation of antimony contamination.
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
(2023)
Article
Chemistry, Physical
Yongfang Zhou, Thomas J. A. Slater, Xuanli Luo, Yi Shen
Summary: By supporting single copper atoms on nitrogen doped carbon nanosheets (Cu/NCNSs), they were used as a versatile single atom electrocatalyst for biomass upgrade. The activity of Cu/NCNSs was compared with commercial Cu nanoparticles for the electro-oxidation of basic platform compounds. The reaction pathways and mechanisms of substrate oxidation on Cu/NCNSs and Cu NPs were studied. This work expands the application of single atom electrocatalysts in biomass upgrade and provides a new route for fabricating advanced electrocatalysts for biomass valorization.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2023)
Article
Chemistry, Physical
Chengwu Qiu, Yaroslav Odarchenko, Ines Lezcano-Gonzalez, Qingwei Meng, Tom Slater, Shaojun Xu, Andrew M. Beale
Summary: HAADF-STEM imaging and electron energy loss spectroscopy (EELS) were used to show that the presence of residual C12E4 surfactant on the surface of a TiO2 rutile support prevents the formation and migration of Ti3+/Ti2+ oxides and therefore TiO2-x. Additionally, the surfactant residues prevent the coalescence and aggregation of CoNPs during catalyst preparation, maintaining their dispersion and leading to a greater number of active Co species in the Co/TiO2 catalyst.
JOURNAL OF CATALYSIS
(2023)
Article
Chemistry, Multidisciplinary
Wenyuan Huang, Qingqing Mei, Shaojun Xu, Bing An, Meng He, Jiangnan Li, Yinlin Chen, Xue Han, Tian Luo, Lixia Guo, Joseph Hurd, Daniel Lee, Evan Tillotson, Sarah Haigh, Alex Walton, Sarah Day, Louise Natrajan, Martin Schroeder, Sihai Yang
Summary: This study reports the direct synthesis of N-formamides by coupling reductive amination of carbonyl compounds and CO2 fixation. A ruthenium catalyst supported by a metal-organic framework was used to achieve highly selective production of N-formamides. The presence of host-guest binding interactions between the catalyst and adsorbed substrates facilitated the activation of substrates and promoted selectivity.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Ilya Popov, Sadegh Ghaderzadeh, Emerson C. Kohlrausch, Luke T. Norman, Thomas J. A. Slater, Gazi N. Aliev, Hanan Alhabeadi, Andre Kaplan, Wolfgang Theis, Andrei N. Khlobystov, Jesum Alves Fernandes, Elena Besley
Summary: This work provides a comprehensive guidance on increasing the degree of atomization of metal catalysts by selecting appropriate experimental conditions and supports. It is based on a rigorous macro-kinetic theory that captures competing processes of nucleation and formation of single atoms stabilized by point defects. The effects of metal-support interactions and deposition parameters on the ratio of single atom to nanocluster, as well as the role of metal centers formed on point defects in nucleation kinetics, have been established, paving the way for guided synthesis of single atom catalysts. Experimental results on sputter deposition of Pt on exfoliated hexagonal boron nitride, imaged by aberration-corrected scanning transmission electron microscopy, support these predictions.
Article
Chemistry, Multidisciplinary
Yi-Chi Wang, Thomas J. A. Slater, Gerard M. Leteba, Candace I. Lang, Zhong Lin Wang, Sarah J. Haigh
Summary: Tailoring the composition and morphology of nanoparticles is crucial for improving their catalytic performance. This study presents an in situ 3D imaging methodology using single particle reconstruction (SPR) that allows for the investigation of structural transformations and elemental redistribution in nanoparticles. The methodology is applied to study the restructuring of PtNi nanoparticles at elevated temperatures and reveals a transition from a disordered to an ordered phase. The changes in structure and elemental distribution are correlated with a decrease in catalytic activity. This in situ SPR methodology can be extended to study nanoparticle evolution in various environments.
Article
Chemistry, Physical
James Paterson, David Brown, Sarah J. Haigh, Philip Landon, Qizhen Li, Matthew Lindley, Mark Peacock, Hendrik van Rensburg, Zhuoran Xu
Summary: Fischer-Tropsch (FT) synthesis is being reconsidered due to its potential in producing sustainable fuels from renewable sources. In this study, a new catalyst support material called manganese titanate showed a switch in selectivity from oxygenated products to high quality linear paraffins. The performance of the MnTiO3 support material was substantially different from conventional Mn impregnated TiO2 support, and only required a modest thermal treatment for activation. The cobalt supported on MnTiO3 also exhibited higher selectivity and conversion compared to the conventional Co/Mn/TiO2 catalyst.
CATALYSIS SCIENCE & TECHNOLOGY
(2023)
Article
Engineering, Electrical & Electronic
Wendong Wang, Nicholas Clark, Matthew Hamer, Amy Carl, Endre Tovari, Sam Sullivan-Allsop, Evan Tillotson, Yunze Gao, Hugo de Latour, Francisco Selles, James Howarth, Eli G. Castanon, Mingwei Zhou, Haoyu Bai, Xiao Li, Astrid Weston, Kenji Watanabe, Takashi Taniguchi, Cecilia Mattevi, Thomas H. Bointon, Paul V. Wiper, Andrew J. Strudwick, Leonid A. Ponomarenko, Andrey V. Kretinin, Sarah J. Haigh, Alex Summerfield, Roman Gorbachev
Summary: We report a polymer-free technique for assembling van der Waals heterostructures using flexible silicon nitride membranes. This technique allows the fabrication of high-quality heterostructures in harsher environmental conditions, resulting in improved electronic and optoelectronic behavior. Specifically, we demonstrate the improved homogeneity of moire superlattices in twisted-graphene heterostructures assembled using this technique.
NATURE ELECTRONICS
(2023)
