Article
Materials Science, Multidisciplinary
Z. Benzarti, A. Khalfallah, Z. Bougrioua, M. Evaristo, A. Cavaleiro
Summary: This study investigates the impact of Mg doping concentration in GaN thin films on their physical and mechanical properties, specifically on their conductivity transition, luminescence, hardness, Young's modulus, and creep behavior. The results demonstrate that an increase in the Mg concentration leads to a conductivity transition from n-type to p-type, with the highest hole concentration and blue luminescence attained at a specific Mg concentration. Moreover, the hardness, Young's modulus, and the intensity of compressive stress increase with the Mg flow rate.
MATERIALS CHEMISTRY AND PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Ali Khalfallah, Zohra Benzarti
Summary: This paper investigates the mechanical properties and creep behavior of undoped and Mg-doped GaN thin films grown on sapphire substrates using MOCVD. The Mg-doped GaN layer is systematically analyzed to compare its mechanical properties and creep behavior to those of the undoped GaN thin film. The results show that Mg doping impacts the hardness, Young's modulus, and creep behavior of the GaN thin films, highlighting its potential impact on technological applications.
Article
Nanoscience & Nanotechnology
Maxim Varenik, Juan Claudio Nino, Ellen Wachtel, Sangtae Kim, Sidney R. Cohen, Igor Lubomirsky
Summary: This research investigated the mechanical and electromechanical properties of dense ceria ceramics doped with trivalent lanthanides. The results showed significant differences in frequency response among different dopants in cerium oxide ceramics, and smaller dopants like Lu and Yb continued to generate usable electrostrictive strain at higher frequencies.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Materials Science, Multidisciplinary
S. Esmizadeh, H. Haftbaradaran
Summary: In this study, a Monte Carlo model is developed to investigate the effect of stress fields of edge dislocations on the distribution of point defects in nonstoichiometric ionic solids. The model takes into account the interaction between point defects and the elastic stress field of dislocations, as well as the electrostatic interaction between point defects. The results show that the distribution of point defects depends on the ionic radius of dopants.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2023)
Article
Chemistry, Multidisciplinary
Evgeniy Makagon, Olga Kraynis, Rotraut Merkle, Joachim Maier, Igor Lubomirsky
Summary: The study finds that doping decreases Young's modulus, and nominally dry samples generally have higher Young's modulus. All samples exhibit large non-classical electrostriction effects.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
Soheil Karimi Aghda, Denis Music, Yeliz Unutulmazsoy, Heng Han Sua, Stanislav Mraz, Marcus Hans, Daniel Primetzhofer, Andre Anders, Jochen M. Schneider
Summary: Ion irradiation induces changes in the structure and mechanical properties of (V,Al)N thin films, with higher ion kinetic energy resulting in densification, structural evolution, and stress relaxation. The elastic modulus of the films shows no significant dependence on ion kinetic energy, which can be attributed to the concurrent effects of Frenkel pair formation and evolution of compressive intrinsic stress induced by ion bombardment. The complex interplay of defect generation and annihilation governs the evolution of film stresses and mechanical properties.
Article
Energy & Fuels
Chenliang Hou, Bo Jiang, Ming Li, Yu Song, Guoxi Cheng
Summary: The internal mechanism of how maceral and temperature control the mechanical properties of in situ coal has not been established so far. This study aims to discover the control mechanism of macerals and temperature on the mechanical properties of in situ coal. By linking the macroscopic and microscopic mechanical properties, it was found that the hardness and elastic modulus of macerals adhere to a specific order, and varying temperatures do not transform this order. The content increase of liptinite, vitrinite, and inertinite affects the hardness and elastic modulus of the whole coal differently. Temperature alters the mechanical properties of in situ coal through macerals as an intermediary, and there is a watershed in the effect of temperature on coal mechanical properties.
Article
Nanoscience & Nanotechnology
B. Ernst, S. Keim, U. Tetzlaff
Summary: The influence of orientation on the indentation modulus, hardness, and creep properties of high purity 6-Sn (wt.%: 99.999) was examined using nanoindentation methods. Crystal orientations close to < 100 >, < 110 >, and < 001 > were identified, and continuous stiffness measurements (CSM) and constant load creep tests were performed. The results indicated an orientation dependence in the indentation modulus, hardness, and creep properties.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Materials Science, Ceramics
Ashok Kumar Baral, Yoed Tsur
Summary: Many metal oxides exhibit thermo-chemical expansion that can lead to mechanical failure in devices such as solid oxide fuel cells. This study demonstrates the separation of expansion caused by chemical effects from pure thermal effects using temperature modulated dilatometry. However, different chemical effects at different temperatures complicate the analysis.
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
(2022)
Article
Construction & Building Technology
Eva Binder, Markus Koenigsberger, Rodrigo Diaz Flores, Herbert A. Mang, Christian Hellmich, Bernhard L. A. Pichler
Summary: The stiffness of cementitious materials decreases with increasing temperature. Macroscopic samples of mature cement pastes were subjected to creep compression experiments at different temperatures, and the results were evaluated based on the theory of viscoelasticity and Boltzmann's superposition principle. A multiscale model for creep homogenization of cement paste, accounting for temperature-dependent elastic and creep moduli, was developed based on molecular simulations. The model successfully predicted the experimental results, and the activation energy of the creep modulus was found to be independent of scale, composition, and maturity.
CEMENT AND CONCRETE RESEARCH
(2023)
Article
Construction & Building Technology
Yunhong Yu, Chenguang Shi, Gang Xu, Zeheng Yao, Tianling Wang, You Wu, Xingyu Yi, Houzhi Wang, Jun Yang
Summary: This study investigates the accuracy of nanoindentation in characterizing the aging behavior of asphalt materials and combines it with DSR frequency sweep tests to macroscopically characterize the aging behavior of asphalt mastic. The results validate the accuracy of nanoindentation in characterizing aging performance and show that aging becomes more pronounced closer to the road surface.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Engineering, Biomedical
Dichu Xu, Maria Luisa Hernandez Miranda, Nicholas D. Evans, Bram G. Sengers, Martin Browne, Richard B. Cook
Summary: This study investigated the mechanical properties of thin PAAm hydrogel layers adherent to stiff substrate supports using depth profiling nanoindentation and a poroelastic model for spherical indentation. The results showed that the apparent stiffness and hydraulic conductivity of the thin hydrogel layers were influenced by the constraint of the impermeable substrate. The study also established the relationship between geometrical confinement and the mechanical properties of the thin hydrogel layers.
JOURNAL OF THE MECHANICAL BEHAVIOR OF BIOMEDICAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Yunfei Yu, Mo Cheng, Zicheng Tao, Wuxiao Han, Guoshuai Du, Yanfeng Guo, Jianping Shi, Yabin Chen
Summary: The study finds that the elastic modulus of 2D magnetic material FeTe can be modulated through phase engineering, and the elastic modulus is dependent on the thickness of the material. These findings are of significant importance for understanding and applying 2D magnetic materials in nanodevices.
Article
Forestry
Joseph E. Jakes, Donald S. Stone
Summary: In order to accurately measure mechanical properties of materials like wood cell walls, traditional nanoindentation methods need to be improved to account for the unique characteristics of these polymeric structures.
Article
Chemistry, Multidisciplinary
Yi Xu, Youquan Jia, Carlo Antonini, Yakang Jin, Longquan Chen
Summary: By immersing substrate-supported polymeric nanofilms in water, interfacial nanoblisters are formed as natural platforms for evaluating their mechanical properties. High-resolution force spectroscopy studies reveal that indentation tests must be conducted on the freestanding region around the nanoblister apex under an appropriate loading force to obtain load-independent, linear elastic deformations. The stiffness of the nanoblister increases with decreasing size or increasing covering film thickness, and this size effect can be explained by an energy-based theoretical model. This proposed methodology can provide an exceptional determination of the elastic modulus of the film and has potential applications in relevant fields.
Article
Chemistry, Multidisciplinary
Evgeniy Makagon, Ellen Wachtel, Lothar Houben, Sidney R. Cohen, Yuanyuan Li, Junying Li, Anatoly Frenkel, Igor Lubomirsky
Summary: ECM coupling, driven by electrochemical compositional changes in solids, can cause mechanical instability in Li-ion batteries and solid oxide fuel cells, but also has potential applications in mechanical actuation for Si-integrated microelectromechanical systems.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Computer Science, Interdisciplinary Applications
Juwon Lee, Hyungtae Cho, Il Moon, Igor Lubomirsky, Valery Kaplan, Junghwan Kim, Yuchan Ahn
Summary: The study introduced a novel approach using carbonate melt for the removal of sulfur dioxide, achieving >99.9% removal rate and cost competitiveness by utilizing waste heat through a heat-exchanger network. The proposed flue gas desulfurization process using carbonate melt demonstrated efficient SO2 removal and cost-effective operation.
COMPUTERS & CHEMICAL ENGINEERING
(2021)
Article
Materials Science, Multidisciplinary
Valery Kaplan, Ellen Wachtel, Konstantin Gartsman, Yishay Feldman, Kyoung-Tae Park, Igor Lubomirsky
Summary: A laboratory-scale process has been developed to recycle rare earth metals from end-of-life rare-earth/iron/boron alloy permanent magnets using a 2-hour chlorine gas treatment at 673 K. The treatment produces a clinker powder consisting of rare earth metal chlorides with minimal amounts of other metals, which can be further reduced to metal through electrolysis or metallothermic reduction.
Article
Nanoscience & Nanotechnology
Maxim Varenik, Juan Claudio Nino, Ellen Wachtel, Sangtae Kim, Sidney R. Cohen, Igor Lubomirsky
Summary: This research investigated the mechanical and electromechanical properties of dense ceria ceramics doped with trivalent lanthanides. The results showed significant differences in frequency response among different dopants in cerium oxide ceramics, and smaller dopants like Lu and Yb continued to generate usable electrostrictive strain at higher frequencies.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Physics, Applied
Sushrut Modak, Leonid Chernyak, Alfons Schulte, Minghan Xian, Fan Ren, Stephen J. Pearton, Igor Lubomirsky, Arie Ruzin, Sergey S. Kosolobov, Vladimir P. Drachev
Summary: In experiments, minority hole diffusion length and lifetime were measured independently in Si-doped beta-Ga2O3 Schottky rectifiers irradiated with 18MeV alpha particles and 10MeV protons. Both parameters showed a decrease with increasing temperature. The non-equilibrium minority hole mobility was calculated from the measured diffusion length and lifetime, indicating that hole self-trapping is likely not significant in the 77-295K temperature range.
APPLIED PHYSICS LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Xiao-Dong Zhang, Maxim Varenik, Konstantin Zvezdin, David Ehre, Ellen Wachtel, Zengwei Zhu, Gregory Leitus, Alexander Popov, Anatoly Zvezdin, Tao Peng, Igor Lubomirsky, Xin Guo
Summary: Ceria and its solid solutions with Gd2O3 are important materials with interesting properties and various applications. However, the understanding of ceria's magnetic properties and magnetoelastic coupling is still limited. In this study, forced magnetostriction in Gd2O3-CeO2 solid solution ceramics is characterized, revealing a linear relationship between strain and Gd3+ concentration. The observed strain is attributed to the single-ion magnetostrictive response of Gd3+ to crystal field.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Leah Fuhrman Javitt, Isabelle Weissbuch, David Ehre, Igor Lubomirsky, Meir Lahav
Summary: The study found that electrofreezing is a process involving the attraction and arrangement of specific ions by an electric field, with trigonal planar ions raising the icing temperature and ions with different structures reducing it. Biguanide ions elevate the icing temperature of supercooled water when concentrated near the negatively charged crystal's interfacial water layer, while guanylurea ions act as ice-breakers.
CRYSTAL GROWTH & DESIGN
(2022)
Review
Chemistry, Multidisciplinary
Leah Fuhrman Javitt, Sofia Curland, Isabelle Weissbuch, David Ehre, Meir Lahav, Igor Lubomirsky
Summary: The ability to control the icing temperature of supercooled water (SCW) is of supreme importance in subfields of pure and applied sciences. In this Account, it is demonstrated that heterogeneous electrofreezing of SCW is a chemical process influenced by an electric field and specific ions, by capitalizing on the properties of polar crystals.
ACCOUNTS OF CHEMICAL RESEARCH
(2022)
Article
Chemistry, Multidisciplinary
O. Taichman, V. Kaplan, E. Wachtel, I. Lubomirsky
Summary: Sulfur dioxide in the flue gas from coal-fired power plants poses ecological and health hazards. A study was conducted to investigate the thermal decomposition of carbonyl sulfide gas (COS) for the final stage of the recycling process. The study found that the addition of catalysts did not affect the kinetics of the COS decomposition reaction. Lowering the COS concentration and reducing the flow rate led to increased COS decomposition.
SOLID FUEL CHEMISTRY
(2022)
Article
Chemistry, Physical
Evgeniy Makagon, Junying Li, Yuanyuan Li, Ellen Wachtel, Anatoly Frenkel, Igor Lubomirsky
Summary: An all-solid-state ECM device operating at room temperature was demonstrated recently. It was discovered that metal oxides other than TiOx can also be valuable components in MIEC nanocomposites functioning as working bodies (WBs) in ECM actuation. However, only the V-based composite was suitable for ECM actuation, while the other oxides showed longer response times.
SOLID STATE IONICS
(2022)
Article
Green & Sustainable Science & Technology
Valery Kaplan, Yishay Feldman, Konstantin Gartsman, Gregory Leitus, Ellen Wachtel, Igor Lubomirsky
Summary: This study describes an electrolytic process that can effectively pulverize sintered Nd2Fe14B magnets for further recycling. The experiments show that, in a 2 M KOH solution with a titanium cathode, cm-size magnet fragments can undergo hydrogen decrepitation (HD) to form powder with a grain size below 50 μm.
JOURNAL OF SUSTAINABLE METALLURGY
(2022)
Article
Chemistry, Multidisciplinary
Shiri Dishon Ben Ami, David Ehre, Andrei Ushakov, Tevie Mehlman, Alexander Brandis, Denis Alikin, Vladimir Shur, Andrei Kholkin, Meir Lahav, Igor Lubomirsky
Summary: This study reports a new method for designing pyroelectric crystals decoupled from piezoelectricity. By co-doping centrosymmetric crystals with tailor-made molecules, the polarization of the crystals exhibits two distinct contributions, providing proof of concept for designing pyroelectric materials with reduced piezoelectric coefficient.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Multidisciplinary Sciences
Haiwu Zhang, Nini Pryds, Dae-Sung Park, Nicolas Gauquelin, Simone Santucci, Dennis Christensen, Daen Jannis, Dmitry Chezganov, Diana A. Rata, Andrea R. Insinga, Ivano E. Castelli, Johan Verbeeck, Igor Lubomirsky, Paul Muralt, Dragan Damjanovic, Vincenzo Esposito
Summary: Electrostriction is a property of dielectric materials where a mechanical deformation is induced in response to an applied electric field. This study reports an engineered electrostriction effect achieved through the controlled interfaces of Gd2O3-doped CeO2 and Er2O3-stabilized delta-Bi2O3 on NdGaO3 substrates. The electrostriction coefficient achieved exceeds the best known materials by three orders of magnitude, and is attributed to the coherent strain from interfacial lattice discontinuity.
Article
Chemistry, Analytical
Asaf Cohen, Hagai Cohen, Sidney R. Cohen, Sergey Khodorov, Yishay Feldman, Anna Kossoy, Ifat Kaplan-Ashiri, Anatoly Frenkel, Ellen Wachtel, Igor Lubomirsky, David Ehre
Summary: A protocol for successfully depositing textured Al0.75Sc0.25N films with low growth stress has been proposed, utilizing a TiN intermediate layer for epitaxial growth. This method is compatible with various substrates and allows for deposition of thick films without loss of orientation.
Article
Chemistry, Physical
Tahel Malka, Xiao-Dong Zhang, Ellen Wachtel, Xin Guo, Igor Lubomirsky, David Ehre
Summary: The study focused on the synthesis, preparation protocols and properties of La(OH)3 powder and pellets, highlighting the potential for cold sintering and inter-grain bridges formation under high pressure. The electrical conductivity was found to be temperature-dependent, primarily deriving from proton transfer, suggesting the potential use of dopants to enhance low temperature conductivity.
SOLID STATE IONICS
(2022)
