The Zr-2.5Nb alloy is a typical pressure tube material in heavy water nuclear reactors, and an increase of hydrogen isotope content in the alloy during service can pose major safety risks; hot vacuum extraction-mass spectrometry is an efficient method for evaluating hydrogen isotope concentrations in the Zr-2.5Nb alloy. This work investigates the kinetics and thermodynamic properties of deuterium (D) absorption and desorption of the Zr-2.5Nb alloy using the constant volume adsorption method and the hot vacuum extraction method. In addition to the previously reported volume contraction model, it was observed that at 600 °C and above, the reaction between D and Zr-2.5Nb is dominated by diffusion, while the reaction is predominantly influenced by surface adsorption and dissociation below 600 °C. Phase transition sequence of Zr-2.5Nb deuterides during non-isothermal desorption was established using quantitatively calibrated thermal desorption spectra combined with the phase transition process of deuteride decomposition. These results can provide important references for optimizing the process parameters of the hot vacuum extraction-mass spectrometry method.
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http://dx.doi.org/10.1039/d4cp01512f | DOI Listing |
Nano Lett
January 2025
Department of Mechanical Engineering & Materials Science, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States.
The development of accurate methods for determining how alloy surfaces spontaneously restructure under reactive and corrosive environments is a key, long-standing, grand challenge in materials science. Using machine learning-accelerated density functional theory and rare-event methods, in conjunction with environmental transmission electron microscopy (ETEM), we examine the interplay between surface reconstructions and preferential segregation tendencies of CuNi(100) surfaces under oxidation conditions. Our modeling approach predicts that oxygen-induced Ni segregation in CuNi alloys favors Cu(100)-O c(2 × 2) reconstruction and destabilizes the Cu(100)-O (2√2 × √2)45° missing row reconstruction (MRR).
View Article and Find Full Text PDFACS Nano
January 2025
Department of Physics, National University of Singapore, Singapore 117551, Singapore.
Phase separation plays a crucial role in many natural and industrial processes, such as the formation of clouds and minerals and the distillation of crude oil. In metals and alloys, phase separation is an important approach often utilized to improve their mechanical strength for use in construction, automobile, and aerospace manufacturing. Despite its importance in many processes, the atomic details of phase separation are largely unknown.
View Article and Find Full Text PDFInorg Chem
January 2025
Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured Materials, MOE Key Laboratory of New Processing Technology for Nonferrous Metals and Materials, School of Resources, Environment and Materials, Guangxi University, Nanning 530004, Guangxi, China.
Here, we reported a highly efficient nitrate electroreduction (NORR) electrocatalyst that integrated alloying and heterostructuring strategies comprising FeCo alloy and MoN (FeCo-MoN/NC). Notably, the maximum NH Faraday efficiency (FE) of 83.24%, NH yield of 12.
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
Theoretical Physics Section, Bhabha Atomic Research Centre, Mumbai-400085, India.
Extensive research on ultrashort laser-induced melting of noble metals like Au, Ag and Cu is available. However, studies on laser energy deposition and thermal damage of their alloys, which are currently attracting interest for energy harvesting and storage devices, are limited. This study investigates the melting damage threshold (DT) of three intermetallic alloys of Au and Cu (AuCu, AuCu and AuCu) subjected to single-pulse femtosecond laser irradiation, comparing them with their constituent metals.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Materials, Xiamen University, Xiamen 361005, China.
Advancements in the development of fast-charging and long-lasting microstructured alloying anodes with high volumetric capacities are essential for enhancing the operational efficiency of sodium-ion batteries (SIBs). These anodes, however, face challenges such as declined cyclability and rate capability, primarily due to mechanical degradation reduced by significant volumetric changes (over 252%) and slow kinetics of sodium-ion storage. Herein, we introduce a novel anode design featuring densely packed bismuth (Bi) embedded within highly conductive carbon microspheres to overcome the aforementioned challenges.
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