MRS Advances最新文献

Lithium manganese nickel oxides are a prominent class of materials used for positively charged lithium-ion batteries. Three different archetype stoichiometries of lithium nickel manganese cobalt oxides (NMC) were studied with bulk-sensitive X-ray Raman and surface-sensitive soft X-ray absorption spectroscopy. We have conducted complementary operando battery X-ray experiments on the NMC622 electrode over one full charge and discharge cycle in a specifically designed operando battery cell. The ex situ NEXAFS spectra of the Ni L-edges show distinct differences in their multiplet characteristics depending on the cathode composition. The obtained operando X-ray Raman spectra show changes in the branching ratio of the Ni 2p spectra and confirms that the state of charge of the battery correlates with changes in the bulk of the electrode.

Continuous wave (CW) laser was used to melt micrometer-sized powders mixed with nanoparticles (NPs) such as titanium NPs. Nanoliquids have been known as medium of excellent heat transfer so that commercial nanoliquids are available for more efficient cooling engines and drill bits for oil wells. Nanoliquids may form during the laser melting or sintering of powders that are mixed with NPs of higher melting point than that of powders. During the melting period, NPs may stay in solid phase while the powders become liquid. This powder-transformed to liquid may be viewed as a nanoliquid with solid-state NPs. We discuss the laser melting of powders such as SmCo₅ with titanium NPs including their hardness.

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Cyanobacterial harmful algal blooms (HABs) are a growing challenge for freshwater management, traditionally addressed through phosphorus (P) limitation strategies. However, increasing evidence highlights nitrogen (N) availability as a key driver of bloom initiation and persistence. Here, we report extracellular voltage recordings from Oscillatoria cohorts exposed to four days of N starvation followed by ammonium (NH₄⁺) repletion using 5 mg L^-1. Under N deprivation, electrical signalling developed progressively with a median of 1-2 events min^-1 and amplitudes between 3-4 µV on day 1 and 2, following a marked increase in activity by days 3 and 4, with median spike rates of 5 events min^-1 and amplitudes up to 17 µV. Following NH₄ ⁺ repletion, signalling activity declined within 24 h, indicating rapid restoration of N balance. These results suggest that electrophysiological monitoring can serve as a real-time, non-invasive indicator of nutrient stress in Oscillatoria and provides a potential early warning tool for HAB onset and associated taste and odour (T&O) outbreaks in freshwater systems.

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Supplementary information: The online version contains supplementary material available at 10.1557/s43580-025-01486-3.

In situ γ-irradiated dissolution of the International Simple Glass (ISG) 1 & 2 and a UK high-level waste glass (post-operational-clean-out (POCO)) was investigated following a modified Product Consistency Test-B protocol for 158 d at 40 °C in ultra-high-quality water. Tests were conducted under atmospheric conditions and received a total dose of 21.6 MGy delivered at a rate of 0.137 MGy d^-1. The normalised mass loss of B, Na, Ca and Mg were slightly higher in γ-irradiated tests when compared to non-irradiated tests whilst the normalised mass loss of Si was comparable or slightly lower. Boron-normalised mass losses of 0.87 ± 0.31, 0.60 ± 0.04 and 0.68 ± 0.07 g m^-2 were calculated for γ-irradiated ISG-1, ISG-2 and POCO, respectively, whilst normalised mass losses in non-irradiated controls were 0.62 ± 0.01, 0.57 ± 0.01 and 0.41 ± 0.06 g m^-2. The difference was tentatively attributed to acidification during irradiation.

Graphical abstract: In situ γ-irradiation tests on HLW reference glasses.

Recycling nuclear fuel to recover materials such as uranium and plutonium involves high temperature processes to treat the resulting highly active (HA) waste. This waste contains ruthenium, an important fission product due to its tendency to form volatile compounds and the presence of the radioactive isotope ¹⁰⁶Ru. These properties, combined with the elevated temperatures during HA waste treatment, necessitate a deeper understanding of ruthenium volatilisation mechanisms. Key ruthenium species present or potentially formed in HA waste include nitro and nitrosyl complexes, and ruthenium dioxide (RuO₂). This study focuses on the behaviour of RuO₂ at high temperatures, due to its relevance to the vitrification process used to immobilise HA waste. Preliminary thermogravimetric analysis of commercially available RuO₂ revealed a dehydration process under N₂, O₂, air atmospheres, and volatilisation under oxidising conditions. Post-heating analyses using scanning electron microscopy and X-ray diffraction identified a concurrent, thermally induced recrystallisation process, most prominent under non-oxidising conditions.

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