Europium-doped oxynitride glass powder (Sr-Si-Al-O-N) was synthesized by a sol-gel method followed by ammonolysis to investigate the effect of the ammonolysis conditions on the structure and properties of the glass powder. In particular, the effect of the ammonia gas flow rate during nitridation was studied. The effective nitrogen concentration (Neff) in the obtained powder, analyzed by X-ray fluorescence, increased with an increase in the flow rate, and the results of X-ray photoemission, nuclear magnetic resonance, and Fourier transform infrared (FT-IR) spectroscopy measurements indicated that the population of Si-N bonds increased with an increase in Neff. However, the presence of hydrogen-terminated structures, such as-NHn, in the powder with high Neff was confirmed by FT-IR measurements. The presence of hydrogen-terminated structures, such as-Si-NHn, and the thermal stability of these hydrogen-related structures were further investigated by thermal analyses, including thermal desorption measurements, which suggested that hydrogen-terminated structures can be easily formed during the nitridation of the gel and that the formation of hydrogen-terminated structures inhibits the polymerization of the glass structures.

Porous ceramic supports for gas-separation membranes must combine high gas permeability, good reproducibility, and sufficient mechanical robustness to avoid limiting the performance of thin selective layers under harsh operating conditions. In this study, the fabrication of slip-cast α-Al2O3 porous supports was optimized using an active-learning framework coupled with targeted experiments. Four processing parameters—casting volume, sintering temperature, dwell time, and heating/cooling ramp rate—were explored within a discretized design space comprising approximately 3,600 candidate conditions. Random-forest surrogate models combined with conformal prediction were used to guide experimental selection while accounting for prediction uncertainty and the risk of mechanical failure. Initial experiments revealed a clear trade-off between permeability and mechanical stability: lowering the sintering temperature improved gas permeability but reduced pressure resistance, whereas higher temperatures enhanced mechanical robustness at the expense of permeability. The active-learning optimization identified a favorable processing window centered around 900–1000 °C with increased casting volumes. Compared with the initial process at 1100 °C, the optimized supports exhibited a 24 % increase in N2 permeability and a 31 % reduction in variability while maintaining mechanical integrity under pressures up to 0.6 MPa. These improvements were achieved after experimentally evaluating fewer than 1 % of the accessible parameter combinations. The results demonstrate that active learning provides an efficient strategy for optimizing porous ceramic membrane supports under competing performance constraints while substantially reducing the experimental effort.

BaTiO3–BaO–B2O3–Bi2O3 (BBB) glass composites were investigated to clarify how BBB content and sintering route control low-temperature densification, pore evolution, glass-derived phase redistribution, and crystalline phase development. Densification was assessed using 15 and 30 wt% BBB glass with pressureless sintering (PS) at 600–800 °C and spark plasma sintering (SPS) at 500–800 °C. Monolithic BaTiO3 exhibited limited densification at 800 °C, suggesting that solid-state diffusion was inadequate for consolidation. The addition of BBB facilitated the formation of a transient liquid phase, enhancing glass softening and pore filling. Densification improved with temperature and BBB content under PS, although residual porosity remained, particularly for 15 wt% BBB. SPS significantly modified microstructural evolution, achieving a relative density of 98.28% for 30 wt% BBB at 800 °C due to SPS-assisted liquid redistribution. SEM analysis revealed a shift from interconnected pores to isolated pinholes, with Bi-rich BBB regions redistributing in the BaTiO3 framework. Tetragonal BaTiO3 was the primary crystalline phase, while 30 wt% BBB, after SPS, formed secondary borate phases. These results establish a processing–microstructure–phase relationship for BaTiO3–BBB glass composites and show that BBB-assisted SPS enables low-temperature densification.

This study explored the changes in the electronic structure due to ferroelectric phase transition behavior of BaTiO3. The temperature variations in the electronic structure of a ferroelectric BaTiO3 crystal were investigated via hard x-ray photoemission spectroscopy (HAXPES) using linearly polarized x rays and density functional theory calculations. The observed valence band HAXPES spectra exhibited distinct temperature-dependent shapes owing to the crystalline phase transitions from a high-temperature paraelectric cubic phase to low-temperature ferroelectric phases with tetragonal, orthorhombic, and rhombohedral symmetries. The changes in the valence band spectra agreed with the simulated HAXPES spectra derived from the projected densities of states in the crystalline phases multiplied by the photoionization cross sections. This result suggests that the ferroelectric mechanism in BaTiO3 is of the displacive type, which involves structural phase transformations.

Single crystals of formamidinium (FA)-indium (In)-iodide (I) and chloride (Cl) were synthesized to explore the functionality in hybrid halides involving cations with a d10 electronic configuration. The chemical formulae of the iodide and chloride were determined to be FAInI4 and FA3InCl6, respectively, identifying them as trivalent In (4d10) compounds. Single-crystal X-ray diffraction at room temperature resolved the arrangements of [InI4]tetrahedra and FA ions in FAInI4, which crystallized in a monoclinic (P21/n) cell. In contrast, FA3InCl6 exhibited a transformation to a superlattice structure at lower temperatures; its atomic arrangements were almost entirely resolved at 150 K but not clearly at 200 K or higher. Furthermore, dispersion-corrected density functional theory calculations employed to determine the detailed arrangements of FA ions indicated that these crystal structures were stabilized by the formation of hydrogen bonds between FA ions and the inorganic components. The broadband visible luminescence in FA3InCl6 and the complete luminescence quenching observed in FAInI4, are discussed in terms of interactions between FA ions and the inorganic polyhedra.

RE 0.8 Sr 0.2 NiO 3 epitaxial thin films (with RE = Pr or Nd) are grown by pulsed laser deposition on SrTiO 3 and (LaAlO 3 ) 0,3 (Sr 2 TaAlO 6 ) 0,7 (001) (LSAT). Thin films are reduced in RE 0.8 Sr 0.2 NiO 2 and studied in transport properties. In preliminary transport measurements, the transport behavior is close to superconductivity. A study of the chemical composition of the perovskite phase as well as the infinite phase is carried out to determine the impact of the reduction process. In particular, a reduction in the cationic ratio is visible after the completion of the topotactic reduction. In the second part, the study of the impact of strains on the homogeneity of thin films after reduction is carried out. The control of homogeneity by modulating strains depending on the substrate is discussed.

In this study, we investigate structural disorder and its implications in metal cluster (MC)-based compounds, specifically focusing on Cs2[{Mo6Xi8}Xa6] (X = Cl and Br). Utilizing synchrotron radiation X-ray diffraction, Fourier transform infrared spectroscopy, and luminescence measurements, we examined the incorporation of water molecules into these compounds and their effects on the crystal structure and optical properties. Our findings reveal that the presence of water molecules induces the lattice disorder, particularly the displacement of Cs atoms. Density functional theory calculations, including dispersion corrections (DFT-D), were employed to model superlattices incorporating varying positions and amounts of water molecules. The DFT-D results corroborated experimental data, indicating that water molecules notably impact the lattice structure by causing the Cs disorder without altering the fundamental trigonal arrangement of MC units. Our results reveal that the composition of the compounds, specifically the Cs/[{Mo6Xi8}Xa6] ratio, remains stoichiometric, regardless of the amount of water in their lattice. Luminescence spectroscopies confirmed that the water incorporation and the lattice disorder had little effect on the luminescence wavelength, but purification enhanced the luminescence efficiency. This study highlights the importance of understanding structural disorders in MC-based compounds for optoelectronic applications and demonstrates the utility of DFT calculations in exploring complex crystallographic phenomena.

Eu-doped oxynitride glass films were prepared using a sol–gel process involving ammonolysis. Nitrogen was incorporated into the glass network, and the photoluminescence intensity increased as the ammonolysis holding time increased.

We developed a new penternary wurtzitic nitride system Li1-xZnxGe2-xGaxN3 (0 <= x <= 1) by hybridizing LiGe2N3 and ZnGeGaN3. Fairly stoichiometric fine powder samples were synthesized by the reduction-nitridation process at 900 degrees C. While the end member LiGe2N3 possessed a relatively large band gap of 4.16 eV, the band gap of the developed penternary system varied in a broad range of 3.81 to 3.10 eV, showing promising responsivity to the solar spectrum. The crystal structure of LiGe2N3 was precisely determined by time-of-flight neutron powder diffraction for the first time, revealing the complete ordering of Li and Ge in the Cmc2(1) structure. The structural evolution from completely ordered LiGe2N3 to fully disordered ZnGeGaN3 was quantitatively analyzed by Rietveld refinement based on a partially disordered Cmc2(1) model, and the obtained results were also supported by Ga-71 solid-state NMR spectroscopy. The synthesized Li1-xZnxGe2-xGaxN3 powder samples exhibited photocatalytic activities for the water reduction and oxidation reactions under solar light irradiation, with the H-2 evolution rate of 0.3-59.0 mu mol/h and the O-2 evolution rate of 3.1-296.2 mu mol/h, depending on the composition. Stable solar hydrogen generation of up to 48 h was demonstrated by the x = 0.80 sample, with the total amount of H-2 evolved over 1.6 mmol and an external quantum efficiency of 2.1%.

Hydrogen dynamics in the nanoscale region of VO_2 was investigated by muon spin rotation/relaxation (μSR) technique. Positively charged muon acts as a light radioisotope of proton and can be used as a probe to explore the inside of materials from an atomic perspective. By analyzing the muon hopping rate and the spatial distribution of the ^51V nuclear magnetic moments, we have identified two types of diffusion paths in VO_2 (via oxygen-muon bonds or defects) and the potential of a high diffusion coefficient in the 10^-10 cm^2/s range at ambient temperature. Our results provide valuable information for developing hydrogen-driven VO_2–related electronic devices.

Hydrogen dynamics in the nanoscale region of VO2 was investigated by muon spin rotation/relaxation (mu SR) technique. Positively charged muon acts as a light radioisotope of protons and can be used as a probe to explore the inside of materials from an atomic perspective. By analyzing the muon hopping rate and the spatial distribution of the 51V nuclear magnetic moments, we have identified two types of diffusion paths in VO2 (via oxygen-muon bonds or defects) and the potential of a high diffusion coefficient in the 10-10 cm2/s range at ambient temperature. Our results provide valuable information for developing hydrogen-driven VO2-related electronic devices.

For the extraction of hydrogen from ammonia at low temperatures, we investigated Ni-based catalysts fabricated by the thermal decomposition of RNi5 intermetallics (R = Ce or Y). The interconnected microstructure formed via phase separation between the Ni catalyst and the resulting oxide support was observed to evolve via low-temperature thermal decomposition of RNi5. The resulting Ni/CeO2 nanocomposite exhibited superior catalytic activity of ∼25% at 400 °C for NH3 cracking. The high catalytic activity was attributed to the interlocking of Ni nanoparticles with the CeO2 framework. The growth of Ni nanoparticles was prevented by this interconnected microstructure, in which the Ni nanoparticles incorporated nitrogen owing to the size effect, whereas Ni does not commonly form nitrides. To the best of our knowledge, this is a unique example of a microstructure that enhances catalytic NH3 cracking.

BACKGROUND The prospective Control of HEART rate in inFant and child tachyarrhythmia with reduced cardiac function Using Landiolol (HEARTFUL) study investigated the effectiveness and safety of landiolol, a short-acting β1 selective blocker, in children.Methods and Results: Twenty-five inpatients aged ≥3 months to <15 years who developed supraventricular tachyarrhythmias (atrial fibrillation, atrial flutter, supraventricular tachycardia, and inappropriate sinus tachycardia) were treated with landiolol. The primary endpoint, the percent of patients with a reduction in heart rate ≥20% from the initial rate of tachycardia, or termination of tachycardia at 2 h after starting landiolol, was achieved in 12/25 patients (48.0%; 95% CI 28.4-67.6), which exceeded the predetermined threshold (38.0%). At 2 h after starting landiolol administration, heart rate had decreased by ≥20% in 45.8% (11/24) and recovery to sinus rhythm was achieved in 40.0% (6/15) of the patients. Adverse reactions (ARs) occurred in 24.0% (6/25) of patients, and the study was discontinued in 4.0% (1/25) of the patients; however, none of these ARs were considered serious. The most common AR was hypotension (20.0% [5/25] of patients). CONCLUSIONS The HEARTFUL study has demonstrated the efficacy of landiolol, by reducing heart rate or terminating tachycardia, in pediatric patients with supraventricular tachyarrhythmias. Although serious ARs and concerns were not identified in this study, physicians should be always cautious of circulatory collapse due to hypotension.

Wurtzite-type aluminum scandium nitride [WZ-(Al11xScx)N] thin films were grown on 0.5 wt % Nb-doped SrTiO3(111) (Nb:STO) single crystal substrates using the radio frequency reactive magnetron sputtering method with Al and Sc targets. WZ-(Al11xScx)N thin films with 0 < x < 0.49 were epitaxially grown on Nb:STO sub-strates. Films with x < 0.3 exhibited multi-domain in-plane orientation. The coexistence of two rotation domains, (Al,Sc)N[100]//Nb:STO[11 ⠂0] and (Al,Sc)N[100]//Nb:STO[112 ⠂], was observed. The abundance of these two domains varied with x, and films with x > 0.3 were single-crystal-like single-domain films. Although the lattice parameters and domain structure intricately changed with x, the calculated unit cell volume was in accordance with the Vegard's law. These results indicate that the unit cell volume is determined by the chemical composition.

The electrical properties of GeS single-crystal are determined by the Van der Pauw method as a function of the temperature, thus establishing for the first time the dependence of electrical resistivity on both carrier con-centration and mobility. This was possible after the repeated growth of GeS by vapor transport from molten GeS so that high-purity (low concentration of Fe and Na impurities) and high-crystalline (XRC FWHM = 2 min.) GeS single-crystals could be obtained. An extraordinary high electrical conductivity is observed between 180 and 450 K, ranging from 1.1 x10-2 to 3.7 x10-5 omega- 1 cm-1. Acceptors are activated over the whole temperature range, while donor activation takes place above 280 K, partially compensating the hole carrier concentration. In contrast, the mobility is proportional to T-2.4 over the whole temperature range, indicating the predominance of lattice scattering. At room temperature the electrical conductivity is as high as 6.7 x 10-3 omega- 1 cm-1, originating from a hole concentration of 1.7 x 1015 cm-3 and mobility of 25 cm2/Vs.

The local electronic structure of muons (Mu) as dilute pseudohydrogen in single-crystalline 0-Ga2O3 has been studied by the muon spin rotation/relaxation (mu SR). High-precision measurements over a long time range of similar to 25 mu s have clearly identified two distinct Mu states: a quasistatic Mu (Mu1) and fast-moving Mu (Mu2). By comparing this result with predictions from the recently established ambipolarity model, these two states are respectively attributed to the relaxed-excited states associated with the donor (E+/0) and acceptor (E-/0) levels predicted by density functional theory (DFT) calculations for the interstitial H. Furthermore, the local electronic structure of Mu1 is found to be an OMu-bonded state with three-coordinated oxygen. The structure is almost identical with the thermal equilibrium state of H, and it is found to function as an electron donor. The other Mu2 is considered to be in the hydride state (Mu-) from the ambipolarity model, suggesting that it is in fast diffusion motion through the short-lived neutral state due to the charge exchange reaction with conduction electrons (Mu- F Mu0 + e-).

Room temperature ferroelectricity in unsubstituted AlN films is studied to examine the role of cation substitution into wurtzite materials. AlN and (Al0.7Sc0.3)N films deposited on (111) 0.5 wt. % Nb-doped SrTiO3 have a (0001)-orientation with different in-plane lattice alignments with respect to those of the substrate, depending on the composition and the deposition temperature. The AlN films deposited at 450 °C showed complete ferroelectric switching above 140 °C but local polarization switching at room temperature because a dielectric breakdown occurred before complete switching, while full polarization reversal was observed at all measurement temperatures for (Al0.7Sc0.3)N. Low-temperature deposition, such as at 250 °C, significantly enhanced the dielectric breakdown field and also increased leakage current. As a result, sufficient polarization switching at room temperature was observed in the AlN film deposited at 250 °C. Positive-up/negative-down pulse measurements showed remanent polarization of 150 μC/cm2 and a coercive field of 8.3 MV/cm, in agreement with the theoretical value and temperature dependence observed for the AlN film deposited at 450 °C. The observed coercive field value lies on the line composed of the previously reported data in Sc concentration dependence. This tendency implies that the reduction in the coercive field is primarily attributable to the alteration of crystal lattice anisotropy caused by Sc.