We report on the epitaxial growth of PbTe thin films on CdTe(211)-B substrates by molecular beam epitaxy and identify a unique interfacial relationship characterized by a 180° rotational offset about the [111] axis. High-resolution X-ray diffraction shows that PbTe films grown on CdTe(211)B do not exhibit coherent film peaks along the surface normal. Instead, pole figure analysis reveals emergent diffraction peaks aligned with the [111] axis but rotated 180° relative to the substrate. Complementary 2θ-ω scans confirm that these peaks are independent of the substrate, establishing that the PbTe films are single crystalline and that the rotational offset originates at the interface rather than from twinning. Scanning electron microscopy indicates island-like nucleation with faceted depressions consistent with (111) planes in the thinnest films and improved coverage with thickness, while atomic force microscopy shows a thickness-dependent decrease in RMS roughness and facet angles consistent with growth along the [111] direction. These findings demonstrate the presence of a twisted interface in PbTe/CdTe(211)B heterostructures, broadening the understanding of PbTe on single-crystal CdTe heteroepitaxy beyond the more commonly studied (001) and (111) orientations. The identification of this rotationally offset growth mode provides a foundation for exploring orientation-driven electronic and phonon phenomena with potential applications in thermoelectrics and CdTe-based optoelectronics.

In this paper, two types of hillocks on the β-Ga2O3 (010) epitaxial surface are identified, and their impact on the leakage behavior of the vertical device is investigated. The characteristics of the two types of hillocks are rectangular, elongated in the [001] direction, and square, extended simultaneously along the [001] and [101] directions. The conductive atomic force microscopy (C-AFM) measurements under low reverse bias reveal that the quantity of leakage pixels associated with type II hillocks is tens of times higher than that of type I hillocks, while the intensity of the leakage current for type II hillocks is over 5 nA compared with the picoampere level for type I hillocks. This leakage phenomenon is attributed to the observation of continuous dislocation slipping in a certain direction with interconnected void-like defects inside beneath the type II hillock. The as-fabricated Schottky barrier diode (SBD) devices, through the isolation of defect-free areas, ultimately demonstrate that type II hillocks induce several orders of magnitude higher leakage current than those of type I, identifying type II hillocks as the major leakage channel for (010) β-Ga2O3 vertical devices under low reverse bias conditions.

Birefringent crystals are key materials for polarization and phase control, yet achieving large Δn remains challenging. Here we report two Ge(II)-based organic–inorganic hybrid halides, (H4biimCl)GeCl3 and (H4biimBr)GeBr3 (H2biim = 2,2′-biimidazole). Single-crystal X-ray diffraction shows that protonated (H4biim)2+ units form V-shaped hydrogen-bonded cationic pseudochains via N–H···X hydrogen bonds to a noncoordinating halide anion, while lone-pair-distorted trigonal-pyramidal [GeX3]− units reside between the chains, creating pronounced anisotropy. The compounds exhibit large birefringence values of Δn = 0.263 (Cl) and 0.302 (Br) at 546 nm, in good agreement with first-principles calculations (0.285 and 0.336). Halide substitution (Cl → Br) enhances the polarizability anisotropy of [GeX3]− and increases Δn. These results highlight a viable motif for birefringent crystals by coupling hydrogen-bond-directed π organization with Ge(II) lone-pair distortion.

Bulk crystallization is the commonest method for the high-volume production of pharmaceutical ingredients. As the complexity of both active pharmaceutical ingredient and solvents increases, the behavior of the solute within the solvents may also increase in complexity. This paper compares the nucleation and growth processes of a pharmaceutical ingredient, indomethacin, in three solvents, which span the range of simple to complex. Much of the behavior of indomethacin is mimicked across the solvents, with the γ form of indomethacin crystallizing at low to medium supersaturations. At higher supersaturations, the complex solvents behave as do many other simple solvents in that the solvated β form of indomethacin is found. The great difference in induction time for nucleation and growth time scales for the simple and complex solvents is considered as a function of supersaturation and viscosity and shows that transport processes within the solution play an important role in the crystallization behavior of indomethacin.

Commercial α-lactose monohydrate powders contain trace amounts of lactose phosphate impurities. In this work, the influence of lactose phosphate on the crystallization of α-lactose monohydrate from aqueous solutions is experimentally investigated by varying both the seed mass and the initial supersaturation. A novel approach based on pH measurements is proposed to quantify the concentration of lactose phosphate in solution and its incorporation into lactose crystals during the crystallization process. Deionization of lactose solution prior to crystallization using ion-exchange beads effectively removes the lactose phosphate and enables a clear assessment of the impact of these ionic impurities on the crystallization kinetics and the aspect ratio of the resulting lactose crystals.

The rational design of photocatalytically active metal–organic frameworks is essential for advancing sustainable and selective synthesis. Herein, we report a zirconium-based MOF (Zr-TB-fcu-MOF) assembled from a π-extended, nitrogen-rich benzo(triazole-thiadiazole) linker. The incorporation of a donor–acceptor–donor (D–A–D) architecture within the fcu-type framework induces pronounced intraframework electronic polarization, facilitating efficient photoinduced charge separation under visible-light irradiation. Structural and spectroscopic analyses reveal that the crystalline network exhibits high porosity, suitable band alignment, and good chemical stability. These combined characteristics enable Zr-TB-fcu-MOF to function as a robust and recyclable heterogeneous photocatalyst, promoting the atom-economical synthesis of nitrogen-containing compounds under mild additive-free conditions. The catalyst mediates the formation of symmetrical (up to 85% yield) and unsymmetrical (up to 40% yield) thiadiazoles as well as imines (up to 99% yield), showing good tolerance toward the functional groups present in the tested substrates and maintaining catalytic activity over multiple cycles. This work demonstrates a structure-guided approach for engineering MOF-based photocatalysts with tunable electronic structures for visible-light-driven organic transformations.

Limpets of the family Nacellidae construct their shells with an outer prismatic layer, underlain by an acicular-foliated layer, and occasionally an internal crossed-lamellar layer. The outer layer consists of prisms oriented approximately perpendicular to the shell growth surface. At the transition to the acicular-foliated layer, these prisms subdivide into segments that become incorporated into the underlying folia. The folia are extensive, radially oriented, and further subdivided into transverse acicles, hence the term "acicular-foliated". Crystallographically, the outer prisms are remarkable in having their c-axes oriented at a high angle to their elongation and aligned toward the shell margin, with one a-axis typically perpendicular to the growth surface. The prisms exhibit a high degree of co-orientation, with textures ranging from diffuse to well-organized sheet textures. When considering rhombohedral face orientations, the texture may appear either single- or double-crystal-like. This crystallographic arrangement is inherited by the acicular-foliated layer, where the texture invariably becomes stronger. Such an unusual orientation likely results from oriented nucleation on an organic template, possibly the mantle surface, combined with crystal competition in the direction toward the shell margin. From both morphological and crystallographic perspectives, the prismatic-acicular-foliated microstructural complex of nacellids is unparalleled among molluscs.

Halide perovskites are emerging as promising scintillating materials for X-ray imaging. High-quality X-ray imaging typically requires a short scintillation decay time and high spatial resolution. Herein, a CsPbBr3.03@poly(methyl methacrylate) (PMMA) composite film scintillator, which, using a strategy via overdoping bromine and a polycrystal-polymer composite film preparation method, was designed to achieve fast scintillation and high-resolution X-ray imaging. Excessive doping with bromine shortens the decay time of CsPbBr3.03 powder to a level of subnanoseconds (192.4 ps). In addition, the prepared scintillator has an exciton binding energy of up to 161.75512 ± 10.45011 meV, and exhibits not only a short scintillation decay time of 26.901 ns but also a high spatial resolution of >30 lp·mm–1. This work provides a low-cost and efficient approach for the design of halide perovskite@organic glass composite scintillators, paving the way for the further development of high-resolution X-ray imaging scintillators.

The behavior of 1,2-diiodotetrafluorobenzene (12tfib) as a halogen bond donor was studied by cocrystallizing it witha series of aromatic nitrogen bases covering a wide range of pKa values (2.10 ≤ pKa ≤ 9.60) and comparing the results with those reportedfor other perfluorinated iodobenzenes. The cocrystal screening wasperformed by grinding 12tfib and each of the selectedbases in a 1:2 donor:acceptor stoichiometric ratio as well as crystallizationfrom solution in a small excess of the acceptor (ratio 1:2.5). Ofthe 14 bases used in this study, three weakest bases (pKa below ca. 4) have failed to produce cocrystals, nineintermediate bases (4.85 ≤ pKa ≤6.72) have yielded four new phases, which were only obtainable ingrinding experiments and not as pure samples, four 1:1 cocrystalsand one 1:2 cocrystal, while the two strongest bases (pKa above ca. 7.5) have yielded 1:2 cocrystals. A totalof eight new solids were studied by single-crystal X-ray diffraction.The three 1:2 cocrystals comprise discrete halogen-bonded trimerswith 12tfib acting as a ditopic halogen bond donor totwo base molecules. Among the five 1:1 cocrystals, in two, 12tfib was found to act as a monotopic donor; however, in other three, 12tfib was found to be ditopic, with the nitrogen atom ofthe base being a bifurcated acceptor of a pair of halogen bonds. Thishighly unusual binding motif has been further investigated by quantumchemical calculations and a detailed CSD survey. The computationalstudy has found that a binding site comprising two converging iodineatoms possesses a wide, single minimum potential, which allows fora more favorable binding of weakly and intermediately basic pyridine(aromatic sp2) nitrogen atoms than a single iodine atom.The CSD survey has shown that the aromatic sp2 nitrogenatom acting as a bifurcated halogen acceptor is indeed an extremelyrare occurrence (appearing in only ca. 2.2% of the total) but considerablymore likely to occur in the presence of ortho-diiodohalogen bond donors.