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Structure of metallic glasses fascinates as the generic amorphous structural template for ubiquitous systems. Its specification necessitates determination of the complete hierarchical structure, starting from short-range-order (SRO) → medium-range-order (MRO) → bulk structure and free volume (FV) distribution. This link has largely remained elusive since previous investigations adopted one-technique-at-a-time approach, focusing on limited aspects of any one domain. Reconstruction of structure from experimental data inversion is non-unique for many of these techniques. As a result, complete and precise structural understanding of glass has not emerged yet. In this work, we demonstrate the first experimental pathway for reconstruction of the integrated structure, for Zr 67 Ni 33 and Zr 52 Ti 6 Al 10 Cu 18 Ni 14 glasses. Our strategy engages diverse (× 7) multi-scale techniques [XAFS, 3D-APT, ABED/NBED, FEM, XRD, PAS, FHREM] on the same glass. This strategy complemented mutual limitations of techniques and corroborated common parameters to generate complete, self-consistent and precise parameters. Further, MRO domain size and inter-void separation were correlated to identify the presence of FV at MRO boundaries. This enabled the first experimental reconstruction of hierarchical subset: SRO → MRO → FV → bulk structure. The first ever image of intermediate region between MRO domains emerged from this link. We clarify that determination of all subsets is not our objective; the essence and novelty of this work lies in directing the pathway towards finite solution, in the most logical and unambiguous way. [ABSTRACT FROM AUTHOR]

Copper antimony sulfide (CuSbS2-CSC) is a ternary layered semiconductor material that has been considered an absorber material in thin film solar cells due to its optimal band gap (~1.5 eV) with a high absorption coefficient of over (>104 cm−1). It has attractive optical and electrical properties, as well as earth-abundant, low-cost, and low-toxic constituent elements. The CSC material was prepared by simple ball milling with Sb2S3 and two copper sources: copper acetate and copper chloride. The ground material was placed in the furnace for thermolysis. The temperature was set to 200°C for 1 h for all the samples. In addition, the influence of copper concentration was also analyzed. The prepared material was characterized by X-ray diffraction (XRD), Raman spectroscopy, selected area diffraction (SAED), and transmission electron microscopy (TEM). The XRD patterns confirmed the presence of the CuSbS2 phase in most samples. Some samples show the temperature-dependent phases of CuSbS2, such as Sb2S3 and Cu12Sb4S13. Raman and selected area diffraction (SAED) results were also in accordance with the XRD results. TEM shows the nanosized structure formation of the material. [ABSTRACT FROM AUTHOR]

High-pressure synchrotron based angle dispersive x-ray diffraction (ADXRD) studies were carried out on SmGdO3 (SGO) up to 25.7 GPa at room temperature. ADXRD results indicated a reversible pressure-induced phase transition from ambient monoclinic to hexagonal phase at ∼8.9 GPa. The observed pressure-volume data were fitted with the third order Birch-Murnaghan equation of state yielding zero pressure bulk modulus Bo=132(22) and 177(9) GPa for monoclinic (B-type) and hexagonal (A-type) phases, respectively. Pressure dependent micro-Raman spectroscopy further confirmed the monoclinic to hexagonal phase transition at about 5.24 GPa. The mode Grüneisen parameters and pressure coefficients for different Raman modes corresponding to each individual phases of SGO were calculated using pressure dependent Raman mode analysis. [ABSTRACT FROM AUTHOR]

The RGO-Y2O3 and RGO-Y2O3: Cr3+ (5 mol %) nanocomposite (NC) synthesized by hydrothermal technique. The structure and morphology of the synthesized NCs were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Y2O3:Cr3+ displays spherical-shaped particles. Conversely, the surface of the RGO displays a wrinkly texture connecting with the existence of flexible and ultrathin graphene sheets. The photoluminescence (PL) emission spectra showed series of sharp peaks at 490, 591, and 687 nm which corresponding to 4F9/2 → 6H15/2, 4F9/2 → 6H13/2, and 4F9/2 → 6H11/2 transitions and lies in the blue, orange, and red region. The prepared NCs were used for the preparation of modified carbon paste electrodes (MCPE) in the electrochemical detection of dopamine (DA) at pH 7.4. Both modified electrodes provide a good current response towards voltammetric detection of DA. Doping is an effective method to improve the conductivity of Y2O3:Cr3+ and developed a method for the sensor used in analytical applications. [ABSTRACT FROM AUTHOR]

The communication deals with the eco-friendly synthesis and X-ray crystal structure of an organic carbonitrile, namely 6-amino-3-phenyl-4-(pyridin-4-yl)-2,4-dihydropyrano[2,3-c]pyrazole-5-carbonitrile. The title compound was synthesized in 89% yield by following a simple, straightforward and highly efficient multicomponent one-pot protocol under the excellent catalytic influence of non-toxic trisodium citrate dihydrate under ambient conditions. X-ray diffraction studies reveal the packing of molecules in the crystal, which is strongly influenced by both intra and intermolecular hydrogen interactions. In addition, aromatic π–π interactions stabilize the molecular chains propagating along [001]. [ABSTRACT FROM AUTHOR]

Co-substituted copper ferrites have been synthesized by a microwave-assisted hydrothermal method. X-ray diffraction confirms that Cu1.0Fe2.0O4 presents both tetragonal and CuO monoclinic phases, whereas the Co-substituted copper ferrites are cubic single-phase structures. All materials were crystallized as ultrafine particles with very low sublattice distortions, and the lattice constants vary with the degree of substitution. Fourier-transform infrared and Raman spectroscopies suggest a short range of the crystal lattices. Magnetic analyses demonstrated that each of the ferrites exhibits soft magnetic behavior with low hysteresis loss and coercive force. Electrochemical impedance data indicate a strong relative permittivity and weak dielectric loss tangent to the Co-substituted samples. [ABSTRACT FROM AUTHOR]

Abstract The reversibility of the dehydration of monoclinic CaZn 2 (PO 4 ) 2 ·2H 2 O to the corresponding monohydrate is proven and the dehydration enthalpy determined by combination of thermal analysis and X-ray diffraction. The mechanism of the monohydrate formation is investigated by scanning electron microscopy (SEM) and temperature dependent in situ X-ray powder diffraction. Mechanistic impact on the powder bulk properties are deduced. As for the orthorhombic dimorph, a crystalline monohydrate species is identified and firstly indexed. Thermal induced changes of the lattice parameters up to the formation of the monohydrate are analyzed. A linear elongation of the lattice parallel to the directions [100] and [001] is found. The corresponding elongation coefficients and the volumetric expansion of the unit cell are determined. With regard to the option of synthetic production of the compound, a possible application of the material for thermochemical energy storage and conversion is conceivable. The relevance of fundamental mechanistic features on the bulk behaviour upon cyclic de- and rehydration is discussed. Graphical abstract fx1 Highlights • Reversibility of dehydration of synthetic monoclinic CaZn 2 (PO 4 ) 2 ·2H 2 O to CaZn 2 (PO 4 ) 2 ·H 2 O is proven. • Morphological changes upon dehydration to mono- and anhydrate are investigated. • The diffraction pattern of the monohydrate is presented and indexed. • Lattice constants up to the monohydrate are derived from in-situ XRD measurements. • A topotactic dehydration mechanism is deduced. [ABSTRACT FROM AUTHOR]

Aluminium and its alloys have exceptional corrosion resistant properties, simplicity of fabrication and extraordinary specific strength-to-weight ratio. The main objective of this study is to explore the effect of age hardening on the mechanical properties of tungsten inert gas (TIG) welded joints of the composite. This study highlights the enrichment in mechanical properties like hardness and tensile strength of TIG welded Al6061-SiC composites. A single-pass TIG welding using 5356 filler material is carried out on the composite with varying percentages of SiC having 25 µm. The hardness and tensile strength of the weld zone in as-weld condition is measured. The samples are then subjected to age hardening treatment at different temperatures and the peak hardness values are determined. The tensile strength is noted, and these values are compared with the values of the as-weld condition. The microstructure of the fracture surface in as-weld and peak aged condition is taken and the type of failure mode is found out. X-ray diffraction (XRD) spectra of the peak-aged sample is also considered for the analysis. The results indicated that there was significant influence leading to substantial improvement of hardness and tensile strength values of the samples after the age hardening process. [ABSTRACT FROM AUTHOR]

We report facile synthesis of Cu incorporated multifunctional ZnFe 2 O 4 nanoparticles (Zn 1-x Cu x Fe 2 O 4 ) using simple wet chemical route. The as prepared samples having various Cu cation contents (x = 0 to 0.8) were calcined at 600 °C for 10 h. Samples of particular composition, x = 0.4 (Zn 0·6 Cu 0·4 Fe 2 O 4 ) were calcined at different temperatures (200 °C to 800 °C) to study the effect of calcination on structural and optical properties. X-ray diffraction studies reveal the presence of mixed phases, i.e. normal cubic spinel ferrite and hematite structure (α-Fe 2 O 3 ). Calcination of Zn 0·6 Cu 0·4 Fe 2 O 4 shows further improvement in the crystallinity without segregation of any additional impurity phase. UV-Vis absorbance studies show CuO phase at longer wavelengths for high Cu cation content, while Raman spectral analysis shows the presence of prominent peaks at 220 cm −1 , 287 cm −1 , 400 cm −1 , and relatively weak broad peak at 640 cm −1 corresponding to normal ferrite structure and α-Fe 2 O 3 structure, confirming the X-ray results. [ABSTRACT FROM AUTHOR]

The novel tetrakis β-diketonate of lanthanum complexes M[La(acac)] with a variety of cationic ligands, M = Li, Na and K has been synthesized. The structural and optical characterizations of prepared complexes were carried out by FESEM, FTIR, UV-Vis and PL techniques. A transmittance at around 1600 cm was observed which corresponds to the ketonate group. The excitation spectra of the synthesized complexes show a broad peak in the range of 360-410 nm. Emission spectra were recorded by keeping excitation wavelength fixed at 390 nm. A good intensity emission peak due to O-2p → La-5d transition of LaO was observed at 473 nm. The CIE chromaticity coordinates of all the complexes were observed in the blue region. It could be considered as promising phosphor for blue light emitting materials in OLEDs. [ABSTRACT FROM AUTHOR]

A combined experimental and theoretical study is performed on DMSO solvated 7′-amino-1′,3′-dimethyl- 2,2′,4′-trioxo-1′,2′,3′,4′,4a′,8a′-tetrahydrospiro[indoline-3,5′-pyrano[2,3-d]pyrimidine]-6′-carbonitrile. The compound is studied by NMR, IR spectroscopy, and single crystal X-ray analysis. The crystal structure of the molecule is stabilized by intermolecular N-H…N, N-H…O, and C-H…π interactions. In the crystal, the molecules form hydrogen-bonded chains running along the b axis of the unit cell. In the present work, we have applied density functional theory (DFT) to explore the nonlinear properties of the molecule. The harmonic vibrational frequencies are calculated and compared with experimental FT-IR frequencies. The observed and calculated frequencies are found to be in good agreement. The calculated values of the HOMO-LUMO energy gap shows that a charge transfer occurs within the molecule. [ABSTRACT FROM AUTHOR]

Tin oxide thin films were deposited on well cleaned glass substrates by thermal evaporation in vacuum and were annealed at 500 C in the open atmosphere inside a furnace for 90 min for promoting the sensitivity of the films. The X-ray diffraction studies revealed that the as-deposited films were amorphous in nature and the annealed films showed appreciable crystalline behavior. The annealed thin films were then irradiated using Co gamma source. The radiation induced changes were then studied by X-ray diffraction, scanning electron microscopy, UV-vis spectroscopy and I- V characterization. The remarkable increase in the average grain size, the decrement in the energy band gap and resistivity due to the gamma irradiations up to a certain dose and the reversal of these properties at higher doses are the important observations. The large changes in the conductivity and energy band gap of the annealed thin films due to gamma irradiation make these films quite important device material for the fabrication of gamma sensors and dosimeters. [ABSTRACT FROM AUTHOR]

The effect of seed orientation on the growth rate and aspect ratio of LAP crystals was studied using four different seed orientations, namely (100), (010), (001) and (011), with the aim of achieving the isometric morphology required for device applications. For each experiment the growth rates along the principal crystallographic axes and the aspect ratio of the crystal were quantified. It was found that the growth rate was highest along the b-axis for all the seed orientations investigated and followed the trend Rb ＞ Rc ＞ Ra, which is explained on the basis of low bond strength between the (100) cleavage planes and the relative step energies along the b- and c-axis. The aspect ratio of the crystal grown using (011) oriented seed results in a nearly isometric shape. The structural and optical quality of the (011) oriented crystal was investigated using several optical and X-ray techniques. The optical transmittance was ∼88% for 1064 nm and its 2nd (532 nm) and 3rd (355 nm) harmonics, indicating the usability of the material for frequency conversion applications. The band gap of the materials obtained from the UV cutoff was 5.4 eV. Birefringence interferometry and Mach–Zehnder interferometry showed that the refractive index homogeneity of the crystal is very good. The LDT values (4.8 to 6.6 GW cm−2) show that the crystal is suitable for high-power laser applications. X-ray diffraction topography was used for mapping the defect structure of the crystal and the results were correlated with optical microscopy studies. The above characterizations show that (011) oriented LAP crystal has good optical and structural quality and is suitable for device applications. [ABSTRACT FROM AUTHOR]

The present paper reports on the structural, optical and luminescence properties of Eu doped SnO/FeO and SnO/ZnO nanocomposites synthesized by combustion method. The prepared nanocomposites were characterized by X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), diffuse reflectance and photoluminescence techniques. Control of crystallization and the simultaneous phase formation of SnO, FeO and ZnO in the prepared composites were confirmed by XRD. The FESEM images revealed the irregular aggregated morphology of the nanocomposites. The crystallite size of the nanocomposites increases with increase in Eu concentration. The Eu doped nanocomposites illuminated with ultraviolet light show the characteristic red luminescence corresponding to the D → F transitions of Eu. Different CIE and spectral parameters were calculated using spectral energy distribution function and Judd-Ofelt theory respectively. The photometric characterization indicates the suitability of SnO/ZnO nanocomposite for red emission in different light-emitting applications. [ABSTRACT FROM AUTHOR]

2-Amino-7-methyl-5-oxo-4-phenyl-4,5-dihydropyrano[3,2- c]pyran-3-carbonitrile, CHNO is synthesized via one-pot multi-component reaction at room temperature using commercially available urea as inexpensive and environmentally benign organo-catalyst. Its structure is determined by single-crystal X-ray diffraction technique The crystals are monoclinic, a = 10.7357(12), b = 8.7774(8), c = 15.0759(16) Å, β = 103.575(11)°, Z = 4, sp. gr. P2/ n, R = 0.0551 for 1696 observed reflections. The crystal structure is stabilized by N-H···N, C-H···O, and C-H···π interactions. [ABSTRACT FROM AUTHOR]

Two carbonitrile compounds, 2-amino-4-(3-nitrophenyl)-5-oxo-4,5-dihydropyrano[3,2- c] chromene-3-carbonitrile ( I) and 2-amino-7,7-dimethyl-4-(4-nitrophenyl)-5-oxo-5,6,7,8-tetrahydro-4 H-chromene-3-carbonitrile ( II), were synthesized, and their crystal structures were determined by X-ray diffraction technique. The crystals are triclinic, a = 7.7970(12), 8.2171(7), b = 9.0390(10), 9.2238(7), c = 15.148(2), 14.5585(11) Å, α = 81.439(10)°, 74.895(6)°, β = 75.194(12)°, 87.392(6)°, γ = 76.151(11)°, 78.552(7)°, for I and II, respectively, Z = 2, sp. gr. P $$\overline 1$$. The pyran ring in both the compounds deviates significantly from planarity and adopts boat conformation. The crystal structure is stabilized by N-H···O and N-H···N hydrogen bonds. [ABSTRACT FROM AUTHOR]

The carbonitrile compound, 2-amino-5-oxo-4-propyl-4,5-dihydropyrano[3,2- c]chromene-3-carbonitrile was synthesized, in 83% yield, by one-pot multicomponent reaction of butyraldehyde, malononitrile and 4-hydroxycoumarin using 10 mol% urea as an organo-catalyst at room temperature, and its crystal structure was determined by X-ray diffraction technique. The crystals are triclinic, a = 7.7379(5), b = 8.7520(6), c = 11.6589(5) Å, α = 96.668(4)°, β = 100.033(4)°, γ = 112.547(6)°, Z = 2, sp. gr. P. Both pyran rings in the molecule adopt a boat conformation. The crystal structure is stabilized by N-H···O and N-H···N hydrogen bonds. [ABSTRACT FROM AUTHOR]

Ferroelectric Barium titanate, BaTiO 3 (BTO) thin film has been prepared successfully by sol-gel hydrothermal method (SG-HT) which combines the basic sol-gel process with hydrothermal treatment. High resolution X-ray diffraction (HR-XRD) study reveals single phase polycrystalline tetragonal structure of the prepared BTO thin film. Optical properties were studied using UV- Visible spectroscopy and band gap was found to be 3.51 eV. The I–V characteristics revealed a low dark current (I off ) of 6.07 × 10 -9 A for the prepared BTO thin film which increases to 4.06 × 10 -6 A (I on ) by almost three orders of magnitude when illuminated with UV radiation (λ = 365 nm, Intensity = 24 μW/cm 2 ). The photoconductive gain (K = I on /I off ), was found to be 6.7 × 10 2 . It can be clearly seen that the prepared BTO film can be utilized as an efficient Ultraviolet photodetector. [ABSTRACT FROM AUTHOR]

In the present work, Barium titanate BaTiO 3 (BTO) thin films were prepared by sol - gel spin coating method. High resolution X-ray diffraction study reveals the formation of single phase polycrystalline structure of barium titanate thin films. The films were found to be highly transparent in the visible region and a rough and porous surface morphology which is beneficial for gas sensing applications. Gas-sensing performance of BTO thin film based sensor was studied for varying concentration of NO x gas at room temperature. The sensor showed enhanced response (17.6% to 33.3%) with increase in concentration of NO x gas (50 to 500 ppm). Results highlight the fact that multifunctional BTO films can be exploited for efficient NO x gas even at room temperature. [ABSTRACT FROM AUTHOR]

As-grown and chemically reduced Rh-doped (1500 p.p.m.) KnbO3 single crystals grown by the Czochralski method have been characterized. Reduction of the grown crystals at different levels was carried out under a mixture of CO and CO2 gases as the crystals were grown with excess oxygen. The effect of reduction and poling on crystalline perfection was studied by high-resolution X-ray diffraction (HRXRD) using a multi-crystal X-ray diffractometer developed in-house. The diffraction curves of the as-grown, electrically poled, moderately reduced and heavily reduced single-crystal specimens show remarkable differences. The studies by HRXRD reveal that poling has some influence on the improvement of crystalline perfection, while chemical reduction has a great influence on crystalline perfection; at moderate reduction the crystal becomes nearly perfect, but when the reduction is very heavy the crystal quality decreases slightly, although it is still better than for unreduced samples. Asymmetry of the diffraction curves with respect to the peak position reveals that the as-grown specimens contain a high concentration of both vacancies and self-interstitials. After poling, the concentration of self-interstitial defects is lowered to some extent. When the specimen is moderately chemically reduced, the scattered intensity on both sides of the peak is greatly reduced, showing that the concentrations of both vacancies and interstitials are reduced to a great extent owing to chemical reduction. This clearly indicates that, as a result of the chemical reduction of oxygen in the crystal, crystalline perfection is enhanced significantly. However, under heavy chemical reduction, the number of vacancy defects is increased to a significant extent. Raman scattering, dielectric and photoluminescence studies also show interesting features, with excellent correlation with the degree of crystalline perfection influenced by the processes of reduction and poling. [ABSTRACT FROM AUTHOR]

Novel nanocomposite structure has been made from physical mixing of polymer blend consist PMMA, PEO and PS filled with selenium nanoparticles. The nanocomposite had been deposited on glass slide by drop casting to form a thin film. This film was examined by required instrument like FESEM, XRD, EDS and UV-Vis to show the main physical properties of it. The XRD results were reflected the crystallinity nature of selenium NPs. SEM result shows the porosity nature of prepared film, where the pore size ranging from nano to micro size on all the surface of film. Also the indirect and direct bandgaps estimated and presented and equal to 3.77 and 4 eV. [ABSTRACT FROM AUTHOR]

Pyrochlore Cd2Re2O7 has been investigated under high pressure by x-ray diffraction, resistivity and, midIR reflectance measurements. At ∼14 GPa, the high-temperature cubic pyrochlore phase [space group (SG): Fd3m] undergoes a second-order transition to a rhombohedral structure (SG: R3m) with trigonal distortion in its pyrochlore lattice. Temperature-dependent resistivity p(T ) reveals a large number of exotic electronic phases (including superconducting and unconventional metallic phases) in its P-T phase diagram. At the metalnonmetal boundary (at 21 GPa) the resistivity displays quadratic power-law behavior over a wide T range with possible formation of heavy mass coherent quasiparticles. In the nonmetallic state (dp/dT < 0), the nondivergent and quadratic power-law resistivity as T → 0 reveals the novel character of the ground state. High-pressure optical conductivity measurement evidences electronic correlation playing the vital role in the emergence of the nonmetallic state as the electron-lattice coupling exceeds spin-orbit interaction due to large structural distortion. [ABSTRACT FROM AUTHOR]

Intrinsic defect generated photoluminescence (PL) in zinc oxide nanoparticles (NPs) obtained by a PVA template based wet-chemical process has been studied. A good controllability was achieved on the surface defects, structure and the morphology of ZnO NPs through the variation of solvents used in synthesis. The PL emission strongly depended on the defect structure and morphology. SEM, XRD, annealing and PL excitation studies were used to analyze the types of defects involved in the visible emission as well as the defect concentration. The mechanism for the blue, green and yellow emissions was proposed. The spectral content of the visible emission was controlled through generation/removal of defects through the shape transformation or annealing by focusing on defect origins and broad controls. [ABSTRACT FROM AUTHOR]

Layeredcore–shell bimetallic Cr–Pt nanoparticleswere prepared by the formation and later reduction of an intermediatePt-ion-containing supramolecular complex onto preformed Cr nanoparticles.The resultant nanoparticles were characterized by X-ray diffractionanalysis, transmission electron microscopy, X-ray photoelectron spectroscopy,and aberration-corrected scanning transmission electron microscopy.The results are consistent with the presence of Pt diffusion duringor after bimetallic nanoparticle formation, which has resulted ina Pt/Cr-alloyed core and shell. We postulate that such Pt diffusionoccurs by an electric-field-assisted process according to Cabrera–Motttheory and that it originates from the low work function of the preformedoxygen-defective Cr nanoparticles and the rather large electron affinityof Pt. [ABSTRACT FROM AUTHOR]

The investigation involves preparation and photoluminescence properties of CeO2:Eu3+ (1-11mol%) nano phosphors by eco-friendly green combustion route using Euphorbia tirucalli plant latex as fuel. The final product was characterized by powder X-ray diffraction (PXRD), Scanning electron microcopy (SEM) and Transmission electron microscopy (TEM). The PXRD and SEM results reveals cubic fluorite phase with flaky structure. The crystallite size obtained from TEM was found to be ~20-25nm, which was comparable to W-H plots and Scherrer's method. Photoluminescence (PL) emission of all the Eu3+ doped samples shows characteristic bands arising from the transitions of 5D0→5FJ (J=0, 1, 2, 3, 4) manifolds under excitation at 373 and 467nm excitation. The 5D0→7F2 (613nm) transition often dominate the emission spectra, indicating that the Eu3+ cations occupy a site without inversion center. The highest PL intensity was recorded for 9mol% Eu3+ ions with 5ml latex. PL quenching was observed upon further increase in Eu3+ concentration. The international commission on illumination (CIE) chromaticity co-ordinates were calculated from emission spectra, the values (x, y) were very close to national television system committee (NTSC) standard values of pure red emission. The results demonstrate that the synthesized phosphor material could be very useful for display applications. Further, the phosphor material prepared by this method was found to be non toxic, environmental friendly and could be a potential alternative to economical routes. [ABSTRACT FROM AUTHOR]