Ikaite formation and its transformation to calcite occurs via distinct amorphous calcium carbonates (referred to as I and II) that differ in their morphology, particle size, water content and stability.

X-ray-activated near-infrared luminescent nanoparticles are considered as new alternative optical probes due to being free of autofluorescence, while both their excitation and emission possess a high penetration efficacy in vivo. Herein, we report silicon carbide quantum dot sensitization of trivalent chromium-doped zinc gallate nanoparticles with enhanced near-infrared emission upon X-ray and UV–vis light excitation. We have found that a ZnGa₂O₄ shell is formed around the SiC nanoparticles during seeded hydrothermal growth, and SiC increases the emission efficiency up to 1 order of magnitude due to band alignment that channels the excited electrons to the chromium ion.

We report the mechanically induced chemical decomposition of ${\mathrm{C}}_{60}$-n-pentane. This material is a typical ${\mathrm{C}}_{60}$ clathrate with a well-characterized structure and is stable up to 400 K. However, at room temperature the grinding of ${\mathrm{C}}_{60\mathrm{-}}$n-pentane induces the loss of n-pentane from the originally orthorhombic structure and the material transforms to pure ${\mathrm{C}}_{60}$ with the face-centered-cubic structure. The average crystallite size of the final powder is quite small, from x-ray powder-diffraction peak widths it is estimated to be 150 Å. This unusual chemical decomposition at room temperature points to the highly strained nature of the structure. Similar chemical decomposition might exist for other ${\mathrm{C}}_{60}$ clathrates such as ${\mathrm{C}}_{60}$ acetone.

In the realm of advanced anode materials for lithium-ion batteries, this study explores the electrochemical performance of a high-entropy oxide (HEO) with a unique spinel structure. The equiatomic composition of CrMnFeCoCu was synthesized and subjected to a comprehensive materials characterization process, including X-ray diffraction and microscopy techniques. The multicomponent alloy exhibited a multiphase structure, comprising two face-centered cubic (FCC) phases and an oxide phase. Upon oxidation, the material transformed into a spinel oxide with a minor presence of CuO. The resulting high-entropy oxide demonstrated excellent electrochemical behavior when utilized as an anode material. Cyclic voltammetry revealed distinctive reduction peaks attributed to cation reduction and solid electrolyte interphase (SEI) layer formation, while subsequent cycles showcased high reversibility. Electrochemical impedance spectroscopy indicated a decrease in charge transfer resistance during cycling, emphasizing the remarkable electrochemical performance. Galvanostatic charge/discharge tests displayed characteristic voltage profiles, with an initial irreversible capacity attributed to SEI layer formation. The HEO exhibited promising rate capability, surpassing commercial graphite at higher current densities. The battery achieved 80% (275 mAh g⁻¹) of its initial stable capacity at a current density of 500 mA g⁻¹ by the 312th cycle. Post-mortem analysis revealed structural amorphization during cycling, contributing to the observed electrochemical behavior. This research highlights the potential of HEOs as advanced anode materials for lithium-ion batteries, combining unique structural features with favorable electrochemical properties.