The results presented in this paper, based on the powder X-ray diffraction technique followed by Rietveld analyses, are devoted to the mechanism of silver incorporation in biphasic calcium phosphates. Results were confirmed by SEM observation. Samples were synthesized via the sol-gel route, followed by heat treatments. Two incorporation sites were highlighted: Ca²⁺ replacement by Ag⁺ into the calcium phosphates (HAp: hydroxyapatite and β-TCP: tricalcium phosphate), and the other as metallic silver Ag° nanoparticles (formed by autogenous reduction). The samples obtained were thus nanocomposites, written Ag°/BCP, composed of closely-mixed Ag° particles of about 100 nm at 400 °C (which became micrometric upon heating) and calcium phosphates, themselves substituted by Ag⁺ cations. Between 400 °C and 700 °C the cationic silver part was mainly located in the HAp phase of the composition Ca_10−xAg_x(PO₄)₆(OH)_2−x (written Ag⁺: HAp). From 600 °C silver cations migrated to β-TCP to form the definite compound Ca₁₀Ag(PO₄)₇ (written Ag⁺: TCP). Due to the melting point of Ag°, the doping element completely left our sample at temperatures above 1000 °C. In order to correctly understand the biological behavior of such material, which is potentially interesting for biomaterial applications, its complex doping mechanism should be taken into consideration for subsequent cytotoxic and bacteriologic studies.

Mechanoluminescence is observed in oxynitride glass-ceramics from the BaO-SiO2-Si3N4 chemical system, doped with Eu and Ho. Light emission was investigated by means of uniaxial compression experiments on disks and parallelepipedic bars with constant loading rates ranging from 0.3 to 300 MPa s−1 up to about 500 MPa. In agreement with previous reports on SrAl2O4-based materials [Dubernet et al., Appl. Phys. Lett. 107, 151906 (2015) and Dubernet et al., Sci. Rep. 10, 19495 (2020)], the mechanoluminescence intensity is found proportional to the mechanical power. Nevertheless, in contrast with SrAl2O4, no gain in the intensity is observed at the onset of the unloading stage, but a drop of the photoluminescence intensity during unloading. This stems from different electron trapping populations and associated energy levels for the Ba4Si6O16 phase (the dominant crystallized phase in the present glass-ceramics), which are discussed in light of density functional theory calculations.

Membranes from MOF glasses hold significant promise for gas separations due to the absence of grain boundary diffusion, liquid processibility, and tunability. The inherent high viscosity of MOF melts renders them prone to cracking and further handling, and their propensity to densify at high temperatures and long time in molten state severely limits their upscaling potential. A solution to overcome these limitations is demonstrated by selecting suitable materials that fit the thermal and mechanical behaviour to MOF-glass, enabling processing and making of large, crack-free MOF-glass sheets. This is demonstrated on the example of the well-known MOF-glass former ZIF-62. By optimizing each step of the process – from melting to performance testing – we successfully fabricate a crack-free, self-supported ZIF-62 glass membrane. The microstructure is investigated using microscopy as well as SEM-EDX analysis, confirming homogeneous boundary-free MOF-glass, while gas permeation experiments prove the applicability of MOF-glass as gas separation membrane. The membrane exhibits exceptionally sharp methane molecular sieving cut-off with such low permeability that gas chromatography is unable to detect CH ₄ . We conclude this work by giving a brief outlook of the remaining challenges and perspectives for MOF glasses, envisioning transferability of our approach to other glass-forming systems and their scaling perspectives.

The luminescence properties of green Ba4Si6O16:Eu2+, rare-earths (RE) (RE = Sc, Y, La and Lu except Pm) phosphors are reported. Their long-lasting phosphorescence is discussed in view of trap depths and concentrations determined from thermally stimulated luminescence experiments. A second emission band centered at 439 nm was evidenced at low temperatures, which stems from the substitution of Eu2+ in the two non-equivalent Ba2+ sites of Ba4Si6O16. The mechanoluminescence properties of Ba4Si6O16:Eu2+, RE phosphors are described, and a new mechanoluminescence mechanism is proposed, in the case where RE = Ho3+, involving a trap distribution from 0.694 to 0.924 eV. Mechanical loading (post UV irradiation) induces a decrease in depth of the trap distribution, leading to an increase of the luminescence intensity, whereas a drop of the luminescence intensity is observed upon unloading, following the faster release of the charge carriers.

The thermal stability of zeolites underlies their many applications. Structural collapse usually occurs through a series of reactions, involving an initial low‐density amorphous state (LDA), a high‐density melt (HDA), and, eventually, a dense recrystallization product. The LDA–HDA transition resembles a glass melting process; the HDA phase can sometimes be quenched into a glass. Using isothermal as well as nonisothermal in situ observation methodology on the faujasitic zeolite X and its potassium‐for‐sodium ion‐exchanged derivatives, we find a pronounced mixed‐alkali effect in the characteristic nonisothermal transition temperatures as well as in the isothermal reaction timescale of the LDA–HDA transition. The latter is taken as being directly related to the viscosity of the liquid into which the zeolite framework is melting; the apparent viscosity associated with this melting process was found to reach as high as 10 ¹⁵ Pa ^. s at 740°C. The observed mixed‐alkali effect is similar to the one observed in the dynamics of common oxide glasses and their corresponding melts.