Diffraction Patterns Of Crystals Research Articles

AIEE active novel red-emitting D-π-A phenothiazine chalcones displaying large Stokes shift, solvatochromism and “turn-on” reversible mechanofluorochromism

In an effort to develop red light emitting, AIEE active potential mechanofluorochromic smart materials, a series of novel D-π-A based phenothiazine chalcone derivatives was designed and synthesized. Various aryl groups were appended to the phenothiazine ring with the aim of tuning the donor ability and to regulate the molecular arrangements which could alter the photophysical and mechanofluorochromic (MFC) properties. Photophysical studies revealed an enhanced intramolecular donor-acceptor charge transfer by appending electron donating 4-methoxyphenyl ring on the phenothiazine moiety whereas a bulky 1-naphthyl ring led to reduced intramolecular charge transfer character. Experimental band gap energies of all the derivatives were found to be in range 2.58–2.68 eV. Existence of large Stokes shift (143–221 nm) and positive solvatochromism was observed in solvents of differing polarity. All the derivatives exhibited a yellow emission in non-polar solvent (toluene) and red emission in polar solvent (DMSO). Chalcone with naphthyl ring displayed maximum AIEE characteristics. Reversible “off-on-off” mechanofluorochromic behaviour was observed upon the subsequent exposure of mechanical stress and dichloromethane vapours or heat. Single crystal X-ray diffraction pattern analysis indicated the presence of twisted conformations and weak intermolecular interactions which are responsible for the mechanofluorochromic behaviour. Powder X-ray diffraction patterns revealed the transformation from crystalline to amorphous state upon mechanical grinding which were reversed upon exposure of dichloromethane vapours or heat.

Crystal structure and diffraction pattern of Ni thin film

The crystal structure of Nickel (Ni) thin film has fascinated the material science research groups. An area in which Ni has found applications is the usage of thin films, which are essential in modern technologies and their optimization is the focus of continued growing research. Its application in thin films promotes the fabrication of nanostructured materials. The structural parameters are calculated by crystal visualization and molecular visualization and functional program, diamond software. The table of angles and the powder diffraction pattern of nickel (Ni) is main focus of this research work.

Guanine and 7,8-Dihydroxanthopterin Reflecting Crystals in the Zander Fish Eye: Crystal Locations, Compositions, and Structures.

The eyes of many fish contain a reflecting layer of organic crystals partially surrounding the photoreceptors of the retina, which are commonly believed to be composed of guanine. Here we study an unusual fish eye from Stizostedion lucioperca that contains two layers of organic crystals. The crystals in the outer layer are thin plates, whereas the crystals in the inner tapetum layer are block-shaped. We show that the outer layer indeed contains guanine crystals. Analyses of solutions of crystals from the inner layer indicated that the block-shaped crystals are composed of xanthopterin. A model of the structure of the block-shaped crystals was produced using symmetry arguments based on electron diffraction data followed by dispersion-augmented DFT calculations. The resulting crystal structure of xanthopterin included, however, a problematic repulsive interaction between C═O and N of two adjacent molecules. Knowing that dissolved 7,8-dihydroxanthopterin can oxidize to xanthopterin, we replaced xanthopterin with 7,8-dihydroxanthopterin in the model. An excellent fit was obtained with the powder X-ray diffraction pattern of the biogenic crystals. We then analyzed the biogenic block-shaped crystals in their solid state, using MALDI-TOF and Raman spectroscopy. All three methods unequivocally prove that the block-shaped crystals in the eye of S. lucioperca are crystals of 7,8-dihydroxanthopterin. On the basis of the eye anatomy, we deduce that the guanine crystals form a reflective layer producing the silvery color present on part of the eye surface, whereas the block-shaped crystals backscatter light into the retina in order to increase the light sensitivity of the eye.

Molten salt assisted growth of lead-free BCZT crystals: effects of synthesis conditions and sintering on structural and electrical properties

An attempt of preparing lead free [(Ba0.85Ca0.15)(Zr0.1Ti0.9)O3] (BCZT) crystals by molten salt synthesis (MSS) method and the influence of MSS process parameters on the morphology, phase structure, dielectric and ferroelectric properties of BCZT ceramic have been reported in this investigation. A reduction in reaction temperature of 350 °C (1000 °C/4 h in MSS method versus 1350 °C/4 h in conventional solid state method) has been achieved in MSS method. Among various alkali metal salts NaCl–KCl salt mixture has been found most effective in producing phase pure and anisotropic platelet like BCZT crystals. Powder X-ray diffraction pattern and Raman spectra of the BCZT crystals confirm the room temperature tetragonal structure of the BCZT ceramic. Finally, BCZT template prepared by alkali metal salts (Na2SO4, NaCl, KCl, NaCl–KCl and NaBr) at 1000 °C/4 h were compacted and sintered at 1450 °C/2 h to achieve pellets with good sintered densities. The crystal structure, microstructural and electrical properties were compared with randomly-oriented BCZT ceramics prepared by conventional solid-state synthesis method, and the results are presented in this paper.

3D printed oral theophylline doses with innovative ‘radiator-like’ design: Impact of polyethylene oxide (PEO) molecular weight

Despite the abundant use of polyethylene oxides (PEOs) and their integration as an excipient in numerous pharmaceutical products, there have been no previous reports of applying this important thermoplastic polymer species alone to fused deposition modelling (FDM) 3D printing. In this work, we have investigated the manufacture of oral doses via FDM 3D printing by employing PEOs as a backbone polymer in combination with polyethylene glycol (PEG). Blends of PEO (molecular weight 100 K, 200 K, 300 K, 600 K or 900 K) with PEG 6 K (plasticiser) and a model drug (theophylline) were hot-melt extruded. The resultant filaments were used as a feed for FDM 3D printer to fabricate oral dosage forms (ODFs) with innovative designs. ODFs were designed in a radiator-like geometry with connected paralleled plates and inter-plate spacing of either 0.5, 1, 1.5 or 2 mm. X-ray diffraction patterns of the filaments revealed the presence of two distinctive peaks at 2θ = 7° and 12°, which can be correlated to the diffraction pattern of theophylline crystals. Blends of PEO and PEG yielded filaments of variable mechanically resistance (maximum load at break of 357, 608, 649, 882, 781 N for filament produced with PEO 100 K, 200 K, 300 K, 600 K or 900 K, respectively). Filaments of PEO at a molecular weight of 200–600 K were compatible with FDM 3D printing process. Further increase in PEO molecular weight resulted in elevated shear viscosity (>104 Pa.S) at the printing temperature and hindered material flow during FDM 3D printing process. A minimal spacing (1 mm) between parallel plates of the radiator-like design deemed essential to boost drug release from the structure. This is the first report of utilising this widely used biodegradable polymer species (PEOs and PEG) in FDM 3D printing.

Mechanical properties of anhydrous oxalic acid and oxalic acid dihydrate.

The mechanical properties of oxalic acid dihydrate and anhydrous oxalic acid (α and β polymorphic forms) were obtained by using rigorous theoretical solid-state methods based on density functional theory using plane waves and pseudopotentials. The calculated crystal structures and X-ray powder diffraction patterns of these materials were found to be in excellent agreement with the experimental information. Since the calculated elasticity matrices fullfilled the Born stability conditions, the corresponding crystal structures were found to be mechanically stable. A large number of relevant mechanical properties including the values of the bulk moduli and their pressure derivatives, shear and Young moduli, Poisson ratios, ductility and hardness indices, and mechanical anisotropy values of these materials were reported. The three forms of oxalic acid are highly anisotropic ductile materials having low hardness and bulk moduli. The three materials are shown to display small negative Poisson ratios (NPR) and to exhibit the phenomenon of negative linear compressibility (NLC) for applied pressures along the direction of the minimum Poisson ratio. In addition, they undergo pressure induced phase transitions for relatively small applied pressures. The analysis of the crystal structures of these materials as a function of pressure demonstrates that the mechanism of NLC of these materials is unrelated to the wine-rack structural mechanism commonly used to rationalize this phenomenon. The three forms of oxalic acid considered in this work are molecular crystals whose structures are characterized by structural elements which are not directly bonded but held together by weak van der Waals forces. The weak bonding between these elements is able to accommodate the structural variations originating from the application of pressure, but the resulting structural deformations appear to be counterintuitive and lead to the anomalous mechanical behavior of these materials.

Mechanical behavior of crystalline ionic porphyrins

Mechanical properties of six different binary ionic porphyrin crystals with variable morphologies were measured and correlated with their structural properties. These solids were formed from stoichiometric combinations of negatively charged tectons, meso-tetra(4-sulfonatophenyl)porphyrin (TSPP), Cu(II) meso-tetra(4-sulfonatophenyl)porphyrin (CuTSPP), Ni(II) meso-tetra (4-sulfonatophenyl)porphyrin (NiTSPP), and four different cationic tectons, namely, meso-tetra (4-pyridyl)porphyrin (TPyP), tetra([Formula: see text]-methyl-4-pyridyl)porphyrin (TMPyP), Cu(II) meso-tetra([Formula: see text]-methyl-4-pyridyl)porphyrin (CuTMPyP), Ni(II) meso-tetra([Formula: see text]-methyl-4-pyridyl)porphyrin (NiTMPyP), and tetra(4-aminophenyl)porphyrin (TAPP). Crystal structures were determined from single crystal and powder X-ray diffraction patterns. Scanning electron and atomic force microscopes (SEM and AFM) provided topographical information. The common arrangement of the porphyrin tectons within the crystals is consistent with alternating face-to-face molecular arrangement forming coherent columns along the fast-growing long axis which are held together by electrostatic and [Formula: see text]–[Formula: see text] interactions as well as hydrogen bonding. In acquiring the indentation data of the porphyrin crystals using AFM, stress was applied perpendicular to the direction where ionic and [Formula: see text]–[Formula: see text] bonds dominate the packing. At indent loads [Formula: see text]50 nN/nm2, all the porphyrin structures deformed elastically. Young’s modulus ([Formula: see text] values for the different crystals range from 6 to 28 GPa. In a broader perspective, this study highlights the extraordinary mechanical behavior of porphyrin assemblies formed by ionic self-assembly. Judicious selection of charged porphyrin synthons can yield crystalline materials with mechanical properties that combine the elastic characteristics of ‘soft’ polymers with the stiffness of composite materials. Such high-performance materials are excellent candidates for deformable optoelectronic devices.

Синтез и строение комплексов циркония [Ph3PCH=CHMe]2[ZrCl6] и гафния [Ph3PCH2C(O)Me]2[HfCl6

The interaction of zirconium (IV) chloride and hafnium (IV) cloride with tetraorganylphosphonium chlorides in solutions of acetonitrile synthesized the following complexes: [Ph 3 PCH=CHCH 3 ][ZrCl 6 ] ( 1 ), [Ph 3 PCH 2 C(O)CH 3 ][HfCl 6 ] ( 2 ). The structures 1 and 2 were determined by XRDA and IR. The X-ray diffraction patterns of crystals 1 and 2 were obtained at 293 K on an automatic diffractometer D8 Quest Broker (MoK α radiation, λ = 0.71073 Å, graphite monochromator) the phosphorus atoms of complexes 1 and 2 have a distorted tetrahedral configuration in the cations. [C 42 H 40 P 2 Cl 6 Zr ( 1 ), M = 910.60; the triclinic syngony, the symmetry group P ; cell parameters: a = 10.189(8), b = 14.428(7), c = 15.229(8) Å; a = 83.31(2) degrees, β = 73.77(3) degrees, g = 87.75(3) degrees; V = 2135(2) Å 3 ; the crystal size is 0.72 × 0.36 × 0.3 mm; intervals of reflection indexes –12 ≤ h ≤ 12, –18 ≤ k ≤ 18, –19 ≤ l ≤ 19; total reflections 36133; independent disclosures 7367; R int = 0.0326; GOOF = 1.180; R 1 = 0.0907; w R 2 = 0.2675; residual electron density ­­–0.91/ 0.827 e/Å 3 , C 42 H 40 P 2 Cl 6 O 1 Hf ( 2 ), M = 1029.87; the triclinic syngony, the symmetry group P ; cell parameters: a = 10.323(3), b = 10.721(3), c = 11.122(3) Å; a = 67.634(13) degrees, β = 78.219(17) degrees, g = 73.041(14) degrees; V = 1082.7(5) Å 3 ; the crystal size is 0.57 × 0.39 × 0.22 mm; intervals of reflection indexes –19 ≤ h ≤ 19, –20 ≤ k ≤ 20, –21 ≤ l ≤ 21; total reflections 118390; independent disclosures 16166; R int = 0.0486; GOOF 1.009; R 1 = 0.0447; w R 2 = 0.0772; residual electron density ­–1,013/0,910 e/Å 3 ]. The СРС valence angles are 107.95(16)°–110.94(15)° and 106.72(17)°–113.51(17)° for 1 , 105.85(15)°–110.97(15)° for 2 , distance P-С 1.771(6)–1.801(6) Å и 1.781(6)–1.801(6) Å in 1 ; 1.790(2)–1.821(2) Å in 2 . In octahedral anions [ZrCl 6 ] 2− and [HfCl 6 ] 2– trans-angles ClZrCl and ClHfCl equal 180.0º, distance 2.462(3)–2.476(3) Å и 2.462(2)– 2.468(2) Å in a crystal solvate in 1 , 2.4513(10)–2.462(2) Å in 2 . Complete tables of coordinates of atoms, bond lengths and valence angles are deposited at the Cambridge Structural Data (No. 1913593 for 1 , 1919938 for 2 , deposit@ccdc.cam.ac.uk; http://www.ccdc. cam.ac.uk).

In Vitro Synthesis and Crystallization of β-1,4-Mannan.

In vitro polymerization of β-mannans is a challenging reaction due to the steric hindrance confered by the configuration of mannosyl residues and the thermodynamic instability of the β-anomer. Whatever the approach used to date-whether chemical, or enzymatic with glycosynthases and mannosyltransferases-pure β-1,4-mannans have never been synthesized in vitro. This has limited attempts to investigate their role in the production of plant and algal cell walls, in which they are highly abundant. It has also impeded the exploitation of their properties as biosourced materials. In this paper, we demonstrate that TM1225, a thermoactive glycoside phosphorylase from the hyperthermophile species Thermotoga maritima, is a powerful biocatalytic tool for the ecofriendly synthesis of pure β-1,4-mannan. The recombinant production of this enzyme and its biochemical characterization allowed us to prove that it catalyzes the reversible phosphorolysis of β-1,4-mannosides, and determine its role in the metabolism of the algal mannans on which T. maritima feeds in submarine sediments. Furthermore, after optimizing the reaction conditions, we exploited the synthetic ability of TM1225 to produce β-1,4-mannan in vitro. At 60 °C and from d-mannose 1-phosphate and mannohexaose, the enzyme synthesized mannoside chains with a degree of polymerization up to 16, which precipitated into lamellar single crystals. The X-ray powder diffraction and base-plane electron diffraction patterns of the lamellar crystals unambiguously show that the synthesized product belongs to the mannan I family previously observed in planta in pure linear mannans, such as those of the ivory nut. The in vitro formation of these mannan I crystals is likely determined by the high reaction temperature and the narrow chain length distribution of the insoluble chains.

Maggi-Rubinowicz integral for Fraunhofer diffraction by hexagonal particles: application to cirrus ice crystals.

This paper is devoted to Fraunhofer diffraction by hexagonal ice crystals like those that can be encountered in cirrus clouds. Such crystals are important, for they are the basic building elements of crystals of more complex shape. A new alternative based on the Maggi-Rubinowicz transformation is proposed. This technique, whose basic formula is a line integral version of the Kirchhoff integral, is very easy to implement and is not time consuming. Diffraction patterns of hexagonal ice crystals with (i)fixed arbitrary orientation, (ii)random orientation, and (iii)preferred orientation are given. The topic is of importance since the radiative impact of cirrus clouds, which depends directly on ice crystal optical properties, is still a challenging problem in climate research.

Crystal structure of the thortveitite-related M phase, (MnxZn1-x)2V2O7 (0.75 < x < 0.913): a combined synchrotron powder and single-crystal X-ray study.

The determination of the crystal structure of the M phase, (MnxZn1-x)2V2O7 (0.75 < x < 0.913), in the pseudobinary Mn2V2O7-Zn2V2O7 system for x ≃ 0.8 shows that the previously published triclinic unit-cell parameters for this thortveitite-related phase do not describe a true lattice for this phase. Instead, single-crystal X-ray data and Rietveld refinement of synchrotron X-ray powder data show that the M phase has a different triclinic structure in the space group P-1 with Z = 2. As prior work has suggested, the crystal structure can be described as a distorted version of the thortveitite crystal structure of β-Mn2V2O7. A twofold superstructure in diffraction patterns of crystals of the M phase used for single-crystal X-ray diffraction work arises from twinning by reticular pseudomerohedry. This superstructure can be described as a commensurate modulation of a pseudo-monoclinic basis structure closely related to the crystal structure of β-Mn2V2O7. In comparison with the distortions introduced when β-Mn2V2O7 transforms at low temperature to α-Mn2V2O7, the distortions which give rise to the M phase from the β-Mn2V2O7 prototype are noticeably less pronounced.

Research on the preparation and growth mechanism of ZnO micro/nano nails

High quality zinc oxide (ZnO) micro/nano nails were prepared through thermal evaporation on the Si (100) substrate. Scanning electron microscopy (SEM) image shows that the bottom of the nanometer nails present hexagonal structure. The tip diameter of the micro/nano nails is about 319.9 nm, and the length is over 20 μm. X-ray crystal diffraction (XRD) pattern shows that the sample has a hexagonal wurtzite structure and preferred orientation in (002) direction obviously. Photoluminescence (PL) spectrum shows a strong ultraviolet (UV) luminescence peak near the wavelength of 346 nm. Finally, the growth mechanism of the ZnO micro/nano nails is analyzed and studied.

Dynamical scattering in coherent hard x-ray nanobeam Bragg diffraction

Unique intensity features arising from dynamical diffraction arise in coherent x-ray nanobeam diffraction patterns of crystals having thicknesses larger than the x-ray extinction depth or exhibiting combinations of nanoscale and mesoscale features. We demonstrate that dynamical scattering effects can be accurately predicted using an optical model combined with the Darwin theory of dynamical x-ray diffraction. The model includes the highly divergent coherent x-ray nanobeams produced by Fresnel zone plate focusing optics and accounts for primary extinction, multiple scattering, and absorption. The simulation accurately reproduces the dynamical scattering features of experimental diffraction patterns acquired from a GaAs/AlGaAs epitaxial heterostructure on a GaAs (001) substrate.

Synthesis, structure and characterizations of a new zinc(II) coordination polymer constructed from 3-(1H-pyrazol-4-yl)-5-(pyridin-2-yl)-1,2,4-triazole and isophthalic acid

A new Zinc(II) coordination polymer, {[Zn(ip)(H2L)]·4H2O}n [H2ip = isophthalic acid; H2L = 3-(1H-pyrazol-4-yl)-5-(pyridin-2-yl)-1,2,4-triazole], is reported here. It has been structurally characterized by X-ray single crystal analysis, IR spectra, fluorescence spectroscopy, thermogravimetry analysis and X-ray powder diffraction patterns. It belongs to the triclinic system, space group P-1 with a = 8.7934(3) Å, b = 10.1639(3) Å, c = 12.3203(5) Å, α = 75.174(3)°, β = 81.739(3)°, γ = 79.578(4)°, V = 1041.40(7) Å3, Z = 2, Dc = 1.638 g/cm3, Mr = 513.77, F(000) = 528, R = 0.0344 and wR = 0.0798. The single X-ray diffraction studies reveal that the compound exhibits 2D layer structure. Moreover, thermal behavior and luminescence properties of the compound were also studied.

Parameterization of rotations in reference frames with redundant crystallographic axes

Parameterizations of rotations in three-dimensional space are fundamental for description of crystallographic textures. Such parameterizations (e.g., Rodrigues parameters) are usually specified using orthonormal coordinate systems, whereas bases of crystal lattices are generally non-orthogonal. In the case of crystals with hexagonal or rhombohedral lattices, the reference frames involve redundant crystallographic axes, and hence a question arises about feasibility of the generalization of the rotation parameterizations to such frames. The definition of Rodrigues parameters can be extended so they are directly linked to non-Cartesian bases of crystal lattices. The new Rodrigues parameters are contra- or covariant components of vectors specified with respect to exactly the same lattice basis as atomic positions in a unit cell. The generalized formalism allows for using redundant crystallographic axes. Also the orientation matrices can be represented in such frames. The Rodrigues parameterization in non-Cartesian coordinate frames is convenient for crystallographic applications because the generalized parameters are directly related to indices of rotation-invariant lattice directions and to Miller indices of rotation-invariant lattice planes. In the case of the hexagonal and rhombohedral lattices, the frames with redundant axes are used to account for lattice symmetry, but one may apply such frames for other reasons. They can be convenient for handling arbitrary symmetries, in particular symmetries arising in description of some phenomena or symmetries of physical processes. The practicality of frames is illustrated by an alternative description of body-centered lattices, a formula for lattice rotation in deformation by slip, and a new interpretation of indexing of single crystal diffraction patterns.

Biodegradation of Poly (3-hydroxybutyrate) /Eggshellsystems

In this work, biocomposites of poly (3-hydroxybutyrate) (PHB) / calcium carbonate from Rhea Americana eggshells were prepared and the effects of the addition of the inorganic filler in the polymeric matrix were assessed. The residue (powder) of the eggshell calcined at 400 oC or in natura was inserted into a PHB solution for preparation of films via casting. Powder samples were characterized by X-Ray Fluorescence (XRF), X-Ray diffraction (XRD) and Thermogravimetry (TG/DTG) and films were characterized by X-Ray diffraction (XRD), Scanning Electron Microscopy (SEM) and biodegradation tests according to the ASTM G 160-03 norm: the results were reported as weight loss and visual inspection by optical microscopy (OM). From the results of the XDR, it was perceived that the peaks in the diffractograms of the powder obtained by milling the Rhea Americana eggshells corresponded to the diffraction patterns of the Calcite crystals, which is a calcium carbonate polyform, and that the calcination preserved the crystalline structure, maintaining the calcium carbonate in the samples. For the biocomposites, a peak characteristic to the calcium carbonate in 29.57o was detected, indicating the insertion of the filler to the polymer matrix. Through SEM the presence of small agglomerates, probably due to polymer particles that were not dissolved, was observed for the pure PHB film. With the addition of the filler in natura a greater porosity was formed in the surface of the biocomposite films, and with the calcined filler, homogeneous films with reduced porosity were obtained. From the weight loss and OM results, it was observed that the filler inserted into the polymeric matrix catalyzes the biodegradation process up to 60 days evaluation in different ways, depending on the type of sample used.

FELIX: an algorithm for indexing multiple crystallites in X-ray free-electron laser snapshot diffraction images.

A novel algorithm for indexing multiple crystals in snapshot X-ray diffraction images, especially suited for serial crystallography data, is presented. The algorithm, FELIX, utilizes a generalized parametrization of the Rodrigues-Frank space, in which all crystal systems can be represented without singularities. The new algorithm is shown to be capable of indexing more than ten crystals per image in simulations of cubic, tetragonal and monoclinic crystal diffraction patterns. It is also used to index an experimental serial crystallography dataset from lysozyme microcrystals. The increased number of indexed crystals is shown to result in a better signal-to-noise ratio, and fewer images are needed to achieve the same data quality as when indexing one crystal per image. The relative orientations between the multiple crystals indexed in an image show a slight tendency of the lysozme microcrystals to adhere on ([Formula: see text]10) facets.

Crystallographic studies of Ba12Nb8-xTaxCo4O36 (x=1,3,4,5,7)

Crystal structures and X-ray reference powder diffraction patterns have been determined for the Ba12Nb8-xTaxCo4O36 (x = 1, 3, 4, 5, 7) series. Ba12Nb8-xTaxCo4O36 crystallize in the cubic perovskite structure with a space group Pm3¯m (No. 221) and the lattice parameter increasing from a = 4.08732(3) Å to a = 4.08894 (2) Å as x varies from 1 to 7. The Goldschmidt distortion parameter for the entire series is about 1.05 (1.0488–1.0506), being similar to that of the cubic end member Ba3Nb2CoO9. Transmission electron microscopy of the composition Ba12Nb4Ta4Co4O36 (or Ba3(NbTaCo)O9) revealed nanoscale 1:2 ordering of Nb/Ta and Co, manifested in the presence of the diffuse superlattice reflections. As this ordering is limited to short range, the average structures were still refined assuming the ideal-perovskite cubic symmetry. X-ray powder diffraction patterns of the studied compounds have been submitted to the Powder Diffraction File (PDF).

An ABX3 organic–inorganic perovskite-type material with the formula (C5N2H9)CdCl3: Application for detection of volatile organic solvent molecules

ABX3 organic–inorganic hybrid perovskite materials, particularly CH3NH3PbI3, have been widely investigated in recent years. However, organic–inorganic hybrid perovskite materials containing N-heterocyclic are still rarely reported. Herein, we discover a new material, namely, (C5N2H9)CdCl3(1) by slow evaporation method. The structure of compound 1 was determinated by single crystal X-ray diffraction patterns, and it exhibits 1D chain based edge-sharing CdCl5 tetragonal pyramid. FT-IR and powder X-ray diffraction patterns (PXRD) were performed to confirm the purity of the prepared crystals. The optical diffuse-reflectance spectra indicate that (C5N2H9)CdCl3 is a wide band-gap semiconductor with optical band gap of 3.50eV. Thermogravimetric analysis (TGA) indicates that 1 is thermally stable up to around 226°C. In addition, based on the measurement of luminescence properties of 1 at room temperature, the emission spectra of 1 shows a blue fluorescent emission peak at 420nm (λex=315nm). And the fluorescence quenching of 1 by acetonitrile has been studied at room temperature.

Evolution of spin correlations in SrDy2O4 in an applied magnetic field

The development of short- and long-range magnetic order induced in a frustrated zig-zag ladder compound SrDy2O4 by an applied field is studied using neutron diffraction techniques. In zero field, SrDy2O4 lacks long-range magnetic order down to temperatures as low as 60 mK, and the observed powder neutron diffraction (PND) patterns are dominated by very broad diffuse scattering peaks. Single crystal neutron diffraction reveals that the zero-field magnetic structure consists of a collection of antiferromagnetic chains running along the c axis and that there is very little correlation between the chains in the ab plane. In an applied magnetic field, the broad diffuse scattering features in PND are gradually replaced by much sharper peaks, however, the pattern remains rather complex, reflecting the highly anisotropic nature of SrDy2O4. Single crystal neutron diffraction shows that a moderate field applied along the b axis induces an up-up-down magnetic order associated with a 1/3-magnetisation plateau, in which magnetic correlation length in the ab plane is significantly increased, but it nevertheless remains finite. The resolution limited k = 0 peaks associated with a ferromagnetic arrangement appear in powder and single crystal neutron diffraction patterns in fields of 2.5 T and above.