Stress-Induced Martensitic Transformation in NaYCl.

Martensitic transformation with volume expansion plays a crucial role in enhancing the mechanical properties of steel and partially stabilized zirconia. We believe that a similar concept could be applied to unexplored nonoxide materials. Herein, we report the stress-induced martensitic transformation of monoclinic NaYCl with an ∼3.

Observation of superconductivity and enhanced upper critical field of η-carbide-type oxide ZrPdO.

We report the first observation of bulk superconductivity of a η-carbide-type oxide ZrPdO. The crystal structure and the superconducting properties were studied through synchrotron X-ray diffraction, magnetization, electrical resistivity, and specific heat measurement. The superconducting transition was observed at T = 2.

Creation of a Highly Active Small Cu-Based Catalyst Derived from Copper Aluminium Layered Double Hydroxide Supported on α-Al O for Acceptorless Alcohol Dehydrogenation.

A highly dispersed carbonate-intercalated Cu -Al layered double hydroxide (CuAl LDH) was created on an unreactive α-Al O surface (CuAl LDH@α-Al O ) via a simple coprecipitation method of Cu and Al under alkaline conditions in the presence of α-Al O . A highly reducible CuO nanoparticles was generated, accompanied by the formation of CuAl O on the surface of α-Al O (CuAlO@α-Al O ) after calcination at 1073 K in air, as confirmed by powder X-ray diffraction (XRD) and Cu K-edge X-ray absorption near edge structure (XANES). The structural changes during the progressive heating process were monitored by using in-situ temperature-programmed synchrotron XRD (tp-SXRD).

Topochemical Synthesis of LiCoF with a High-Temperature LiNbO-Type Structure.

A novel perovskite fluoride, LiCoF, which has an exceptionally low tolerance factor (0.81), has been synthesized via low-temperature lithium intercalation into a distorted ReO-type fluoride CoF using organolithium reagents. Interestingly, this reaction is completed within 15 min at room temperature.

Synthesis and Characterization of High-Entropy-Alloy-Type Layered Telluride BiTe ( = Ag, In, Sn, Pb, Bi).

Recently, high-entropy alloys (HEAs) and HEA-type compounds have been extensively studied in the fields of material science and engineering. In this article, we report on the synthesis of a layered system BiTe where the site possesses low-, middle-, and high-entropy states. The samples with = Pb, AgPbBi, and AgInSnPbBi were newly synthesized and the crystal structure was examined by synchrotron X-ray diffraction and Rietveld refinement.

Important Roles of Water Clusters Confined in a Nanospace as Revealed by a Synchrotron X-ray Diffraction Study.

States of water molecules confined in a nanospace designed by montmorillonite (negatively charged silicate layer) and charge compensating benzylammonium were investigated. Caffeine was used as a probe because of its compatibility for the fine structure of the interlayer water. Powder synchrotron radiation X-ray diffraction (SXRD) and adsorption isotherms of the water vapor revealed a metastable structure of bimolecular water layers (2WLs) in the interlayer space.

Kinetically Stabilized Cation Arrangement in Li YCl Superionic Conductor during Solid-State Reaction.

The main approach for exploring metastable materials is via trial-and-error synthesis, and there is limited understanding of how metastable materials are kinetically stabilized. In this study, a metastable phase superionic conductor, β-Li YCl , is discovered through in situ X-ray diffraction after heating a mixture of LiCl and YCl powders. While Cl arrangement is represented as a hexagonal close packed structure in both metastable β-Li YCl synthesized below 600 K and stable α-Li YCl above 600 K, the arrangement of Li and Y in β-Li YCl determined by neutron diffraction brought about the cell with a 1/√3 a-axis and a similar c-axis of stable α-Li YCl .

Formation Mechanism of β-LiPS through Decomposition of Complexes.

β-LiPS is a solid electrolyte with high Li conductivity, applicable to sulfide-based all-solid-state batteries. While a β-LiPS-synthesized by solid-state reaction forms only in a narrow 300-450 °C temperature range upon heating, β-LiPS is readily available by liquid-phase synthesis through low-temperature thermal decomposition of complexes composed of PS and various organic solvents. However, the conversion mechanism of β-LiPS from these complexes is not yet understood.

Size effect of the guest cation on the AlO framework in aluminate sodalite-type oxides M[AlO](SO) (M = Sr and Ca) in the I43m phase.

Sr[AlO](SO) (SAS) and Ca[AlO](SO) (CAS) are members of the aluminate sodalite-type oxides with the general chemical formula M[AlO](XO) (M is the guest cation and XO is the guest anion). To discuss the role of the guest cations (M = Sr and Ca) on the rotation of AlO in the oxygen tetrahedral framework in the I43m phase, the crystal structure parameters and the probability density function of the guest ions in SAS and CAS have been investigated via synchrotron radiation X-ray powder diffraction by considering Gram-Charlier expansions. The interatomic distances between the M and O ions evaluated from the maximum positions in the probability density distribution are almost equal to the sum of the ideal ionic radii of the M and O ions.

Structural Transition with a Sharp Change in the Electrical Resistivity and Spin-Orbit Mott Insulating State in a Rhenium Oxide, SrReO.

We report the successful synthesis, crystal structure, and electrical properties of SrReO, which contains Re with the 5d configuration. This compound is isostructural with BaReO and shows a first-order structural phase transition at ∼370 K. The low-temperature (LT) phase crystallizes in a hettotype structure of BaReO, which is different from that of the LT phase of SrWO, suggesting that the electronic state of Re plays an important role in determining the crystal structure of the LT phase.

Evolution of two bulk-superconducting phases in SrREFBiS (RE: La, Ce, Pr, Nd, Sm) by external hydrostatic pressure effect.

Polycrystalline samples of SrREFBiS (RE: La, Ce, Pr, Nd, and Sm) were synthesized via the solid-state reaction and characterized using synchrotron X-ray diffraction. Although all the SrREFBiS samples exhibited superconductivity at transition temperatures (T) within the range of 2.1-2.

Crystal Structure and Thermoelectric Transport Properties of As-Doped Layered Pnictogen Oxyselenides NdOFSbAsSe.

We report the synthesis and thermoelectric transport properties of As-doped layered pnictogen oxyselenides NdOFSbAsSe ( ≤ 0.6), which are predicted to show high-performance thermoelectric properties based on first-principles calculation. The crystal structure of these compounds belongs to the tetragonal 4/ space group (No.

Antithermal Quenching of Luminescence in Zero-Dimensional Hybrid Metal Halide Solids.

Zero-dimensional (0D) hybrid metal halides have emerged as a new generation of luminescent phosphors owing to their high radiative recombination rates, which, akin to their three-dimensional cousins, commonly demonstrate thermal quenching of luminescence. Here, we report on the finding of antithermal quenching of luminescence in 0D hybrid metal halides. Using (CNH)SnBr single crystals as an example system, we show that 0D metal halides can demonstrate antithermal quenching of luminescence.

Flux Growth and Superconducting Properties of (Ce,Pr)OBiS Single Crystals.

Ce Pr OBiS (0. 1 ≤ ≤ 0.9) single crystals were grown using a CsCl flux method.

Antiferroelectric to Antiferroelectric-Relaxor Phase Transition in Calcium Strontium Sulfoaluminate.

Structural phase transitions of calcium strontium sulfoaluminate series, (CaSr)[AlO](SO) ((CS)AS-) with = 0.80-1.00, are systematically investigated by powder X-ray diffraction, dielectric measurements, and pyroelectric measurements, to clarify a phase diagram of (CS)AS- ( = 0.

Hydrothermal Synthesis and Crystal Structure of a (BaK)BiO Double-Perovskite Superconductor with Onset of the Transition ∼ 30 K.

A new superconducting double perovskite was successfully synthesized by a low-temperature hydrothermal reaction at 240 °C. The crystal structure refinement of this double perovskite was done by single-crystal X-ray diffraction, and it had a cubic unit cell of = 8.5207(2) Å with space group 3̅ (No.

Why Do Carbonate Anions Have Extremely High Stability in the Interlayer Space of Layered Double Hydroxides? Case Study of Layered Double Hydroxide Consisting of Mg and Al (Mg/Al = 2).

Layered double hydroxides (LDHs) are promising compounds in a wide range of fields. However, exchange of CO anions with other anions is necessary, because the CO anions are strongly affixed in the LDH interlayer space. To elucidate the reason for the extremely high stability of CO anions intercalated in LDHs, we investigated in detail the chemical states of CO anions and hydrated water molecules in the LDH interlayer space by synchrotron radiation X-ray diffraction, solid-state NMR spectroscopy, and Raman spectroscopy.

Defective [Bi O ] Layers Exhibiting Ultrabroad Near-Infrared Luminescence.

Aurivillius phases have been routinely known as excellent ferroelectrics and have rarely been deemed as materials that luminesce in the near-infrared (NIR) region. Herein, it is shown that the Aurivillius phases can demonstrate broadband NIR luminescence that covers telecommunication and biological optical windows. Experimental characterization of the model system Bi Sr Ta O , combined with theoretical calculations, help to establish that the NIR luminescence originates from defective [Bi O ] layers.

An electronic structure governed by the displacement of the indium site in In-S octahedra: LnOInS (Ln = La, Ce, and Pr).

An extremely large displacement of the indium site in In-S octahedra in LnOInS (Ln = La, Ce, and Pr) was found in synchrotron X-ray diffraction. LaOInS with off-center indium in In-S octahedra exhibited a wider optical band gap than CeOInS and PrOInS with on-center indium. Therefore, the electronic structure of LnOInS is governed by the indium site with an extremely large displacement.

Doping-Induced Polymorph and Carrier Polarity Changes in Thermoelectric Ag(Bi,Sb)Se Solid Solution.

Silver bismuth diselenide (AgBiSe) is an n-type thermoelectric material that exhibits a complex structural phase transition from the hexagonal to cubic phase, while silver antimony diselenide (AgSbSe) is a p-type thermoelectric material that crystallizes in the cubic phase at all temperatures. Here, we investigate the crystal structure and thermoelectric properties of Ag(Bi,Sb)Se solid solution, employing AgBiSbSe and AgBiSbSe as representative samples. The carrier polarity of AgBiSbSe is converted from the n-type to p-type by Pb doping, accompanied by a polymorphic change to the cubic phase.

Hydrothermal Synthesis of Pyrochlore-Type Pentavalent Bismuthates CaBiO and SrBiO.

The pyrochlore-type CaBiO and SrBiO have been synthesized from a low-temperature hydrothermal route using NaBiO·nHO as a starting material. The crystal structures of these compounds were refined using synchrotron powder X-ray diffraction data. The cell parameters were found to be a = 10.

X-ray-activated long persistent phosphors featuring strong UVC afterglow emissions.

Phosphors emitting visible and near-infrared persistent luminescence have been explored extensively owing to their unusual properties and commercial interest in their applications such as glow-in-the-dark paints, optical information storage, and in vivo bioimaging. However, no persistent phosphor that features emissions in the ultraviolet C range (200-280 nm) has been known to exist so far. Here, we demonstrate a strategy for creating a new generation of persistent phosphor that exhibits strong ultraviolet C emission with an initial power density over 10 milliwatts per square meter and an afterglow of more than 2 h.