We performed atomic-scale ab initio calculations to investigate the stacking fault (SF) properties of the metastable ζ-ZrH zirconium hydride. The effect of H near the SF was found to entail the existence of negative SF energies, showing that the ζ compound is probably unstable with respect to shearing in the basal plane. The effect of temperature on SFs was investigated by means of free energy calculations in the quasiharmonic approximation. This evidenced unexpectedly large temperature effects, confirming the main conclusions drawn at 0 K, in particular the ζ mechanical instability. The complex behaviour of H atoms during the shear process suggested ζ-hcp → ZrH[Formula: see text]-fcc as a plausible shear path leading to an fcc compound with same composition as ζ. Finally, as shown by an analysis based on microelasticity, this ZrH[Formula: see text]-fcc intermediate compound may be relevant for better interpreting the currently intricate issue of hydride habit planes in zirconium.
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http://dx.doi.org/10.1088/1361-648X/aacedb | DOI Listing |
J Control Release
January 2025
Department of Materials Science, University of Milano-Bicocca, Via R. Cozzi 55, I-20125, Milano, Italy; BioNanoMedicine Center NANOMIB, University of Milano-Bicocca, Italy. Electronic address:
Graphene oxide (GO) is an amphiphilic and versatile graphene-based nanomaterial that is extremely promising for targeted drug delivery, which aims to administer drugs in a spatially and temporally controlled manner. A typical GO nanocarrier features a polyethylene glycol coating and conjugation to an active targeting ligand. However, it is challenging to accurately model GO dots, because of their intrinsically complex and not unique structure.
View Article and Find Full Text PDFACS Nano
January 2025
Instituto de Física de São Carlos, Universidade de São Paulo, São Carlos 13566-590, Brazil.
Monolayers of transition-metal dichalcogenides, such as MoS, have attracted significant attention for their exceptional electronic and optical properties, positioning them as ideal candidates for advanced optoelectronic applications. Despite their strong excitonic effects, the atomic-scale thickness of these materials limits their light absorption efficiency, necessitating innovative strategies to enhance light-matter interactions. Plasmonic nanostructures offer a promising solution to overcome those challenges by amplifying the electromagnetic field and also introducing other mechanisms, such as hot electron injection.
View Article and Find Full Text PDFMaterials (Basel)
December 2024
Neutron Sciences Directorate, Oak Ridge National Laboratory (ORNL), Oak Ridge, TN 37831, USA.
Advanced batteries require advanced characterization techniques, and neutron scattering is one of the most powerful experimental methods available for studying next-generation battery materials. Neutron scattering offers a non-destructive method to probe the complex structural and chemical processes occurring in batteries during operation in truly in situ/in operando measurements with a high sensitivity to battery-relevant elements such as lithium. Neutrons have energies comparable to the energies of excitations in materials and wavelengths comparable to atomic distances in the solid state, thus giving access to study structural and dynamical properties of materials on an atomic scale.
View Article and Find Full Text PDFSci Rep
January 2025
College of Mechanical Engineering, Zhejiang University of Technology, No.18, Chaowang Road, Hangzhou, 310014, Zhejiang Province, China.
To observe the chemical mechanical polishing (CMP) process at the atomic scale, reactive force field molecular dynamics (ReaxFF-MD) was employed to simulate the polishing of 6 H-SiC under three conditions: dry, pure water, and HO solution. This study examined the reactants on the surface of 6 H-SiC during the reaction in the HO solution, along with the dissociation and adsorption processes of HO and water molecules. The mechanisms for atom removal during the CMP process were elucidated.
View Article and Find Full Text PDFAdv Mater
January 2025
School of Materials Science and Engineering, South China University of Technology, Guangzhou, 510641, China.
Understanding the behavior of high-entropy carbides (HECs) under oxygen-containing environments is of particular importance for their promising applications in structural components, catalysis, and energy-related fields. Herein, the structural evolution of (Ta, Ti, Cr, Nb)C (HEC-1) nanoparticles (NPs) is tracked in situ during the oxidation at the atomic scale by using an open-cell environmental aberration-corrected scanning transmission electron microscope. Three key stages are clearly discerned during the oxidation of HEC-1 NPs at the atomic level below 900 °C: i) increased amorphization of HEC-1 NPs from 300 to 500 °C due to the energetically favorable formation of carbon vacancies and substitution of carbon with oxygen atoms; ii) nucleation and subsequent growth of locally ordered nanocluster intermediates within the generated amorphous oxides from 500 to 800 °C; and iii) final one-step crystallization of non-equimolar MeO and MeO (Me = metallic elements, Ta, Ti, Cr, and Nb) high-entropy oxides above 800 °C, accompanied with the reduction in atomic defects.
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