Crystal Thermal Behavior Research Articles

Synthesis, Optical, Electrical, Fluorescence, Dielectric, Thermal, and Mechanical Characterization of 3-Aminopyridine (Scaffold in Drugs) Single Crystal

Objectives: To screen the optical, electrical, fluorescence, dielectric, thermal, and mechanical behavior of the 3-aminopyridine single crystal for its suitability in optoelectronic applications. Methods: A good single crystal of 3-aminopyridine (3-AP) was grown by the slow evaporation method. Findings: The lattice parameters of the grown crystal were determined using a single crystal X-ray diffractometer as, a = 6.184 (4) Å, b = 15.350 (6) Å, c = 5.361 (7) Å and the required functional groups C-N, NH2 bonds of 3-AP were recognized by the FTIR studies. The grown crystal was screened using the UV-Vis-NIR spectrum to understand the transmission and absorption character of the crystal. The various optical constants such as absorption coefficient, optical conductivity, and electrical conductivity of the crystal have been determined from the UV-Vis transmission plot. The lower cut-off wavelength of the 3-AP crystal was observed at 250 nm. The band gap of the grown crystal is found to be 4.5 eV. The emission property of the crystal was studied using fluorescence spectra. Violet, blue, and red emissions are observed from the fluorescence spectra. Thermal screening of the 3-AP crystal was performed using TGA and DTA. The 3-AP crystal remains stable up to 220 ºC and then the crystal begins to decompose up to 260 ºC due to the loss of the -NH2 group of the 3-aminopyridine. The Vickers hardness test revealed the nature of the material as soft type with Meyer’s index (n) of 2. The electronic polarization behavior of the crystal was examined using the dielectric study. Novelty: The lower cut-off wavelength of 250 nm, wide band gap of 4.5 eV, excellent transparency in the entire visible and near-infrared region, violet, blue, and red emission by the material are the distinguishing and mandatory features for optoelectronic applications. These features are good as compared to the 3-AP derivatives reported earlier. Keywords: Unit cell, Absorption, Emission, Conductivity, Strength, Loss

Synthesis, structural, third-order nonlinear optical properties and Hirshfeld surface analysis of 1-((E)-(4-chlorophenylimino)methyl)naphthalen-2-ol

A Schiff base was synthesized via a slow evaporation approach using the condensation reaction of substituted aniline and 2-hydroxy-1-naphthaldehyde. Single Crystal X-Ray Diffraction Analysis, Fourier Transform Infrared Spectroscopy, UV-Visible Spectroscopy, 1H NMR Spectroscopy, and 13C NMR Spectroscopy have all been used to identify it. The crystal space group is explained through crystallography. The structure of crystal was first solved using direct approach, later it was improved using a full-matrix least square strategy. The hydroxyl group and imine are connected by a powerful intramolecular H-bond (N-H·····O) in the crystal structure. The blue color emission is observed for E4CMN in emission spectrum. Assessing Hirshfeld surface was employed to look at supramolecular interactions. For evaluating the thermal behavior of crystals, thermal analysis (TG-DTA) was applied. The compound's surface morphology under the scanning electron microscope (SEM). Using the DFT basis set (B3LYP/6–311 ++G(d,p)), the energy gap (EHOMO, ELUMO), reactivity parameters and Mulliken charges, polarizability(α0), and hyperpolarizability(β0) were determined. Using quantum computations techniques NCI-RDG scatter diagram and scatter graph was obtained and DFT studies, Topological ELF along with LOL parameters are further characterization of E4CMN crystal. The Using a Nd: YAG laser, an open-aperture method of Z-scan analysis was employed to compute NLO absorption of third-order nonlinear optical properties. Nd: YAG laser (532 nm, 10 Hz, 9 ns) with a lowered onset limiting threshold could find that you are a suitable choice for constructing laser security measures in the nanosecond green stimulation region.

Investigation on the synthesis, growth, thermal and optical behavior of creatininium borate single crystal: A potential candidate for nonlinear optical applications

In the this study, we focus on the growth of a metal-organic creatininium borate (CRB) single crystal for third-order nonlinear optical (NLO) applications. Optically transparent & wide optical band gap single crystals of CRB were successfully harvested by adopting a slow evaporation solution technique (SEST) at a constant 40[Formula: see text]C temperature. The structural identification and lattice parameters of the grown sample were determined by powder X-ray diffraction (PXRD) using Rietveld analysis by FullProf Suite software. The occurrence of vacancy/interstitial defects produced during growth was investigated by high-resolution X-ray diffraction (HRXRD) using omega scan arrangement. A single peak with lower full width half maxima (56.4 arc s) was obtained from the scan which suggests that there were no grain boundaries for the grown crystal. Surface morphology and its features such as concentration of dislocations and defect sites on the as-grown sample were scrutinized using the etching technique. The optical band gap and UV–vis cut-off were examined and found to be 5.39 eV and 230 nm, respectively. Photoluminescence characteristics of the crystal show an emission at 377 nm upon excitation with a wavelength of 336 nm. The presence of radiative and non-radiative transitions inside the crystal due to excitation upon 266 nm laser was identified using time-resolved photoluminescence. Thermal stability and decomposition temperature of the compound were obtained by thermo-gravimetric analysis (TGA) and differential scanning calorimetry (DSC). The third-order nonlinearity of the crystal was determined by Z-scan measurement technique with a femtosecond Ti-sapphire laser.

Towards the thermal reactivity and behavior of co-agglomerated crystals of DATB and TATB with attractive nitramines

The thermolysis of the co-agglomerates (CACs) of the attractive nitramines RDX, BCHMX, HMX and CL-20 with 1,3-diamino-2,4,6-trinitrobenzene (DATB) and 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) was studied by means of differential thermal analysis (DTA) and differential scanning calorimetry (DSC), using the Kissinger method for output evaluation. The insertion of both DATB and TATB molecules into nitramine crystal lattices markedly increased the thermal sensitivity of the resulting CACs to overheating. Depression in melting points was detected in all CACs and, with the exception of RDX CACs, also in the exothermic peaks. The RDX CACs differ from the other studied CACs by their decomposition in the liquid state. The activation energies (Ea), obtained correlate with asymmetric N-O stretching vibrations, confirming the important influence of ‒N‒O····H‒H= interactions in CACs; a similar correlation with asymmetric NO2 stretching confirms the interactions of DATB and TATB molecules with nitramine molecules through van der Waals forces. The insertion of DATB or TATB into the crystal lattice of HMX or CL20 changes their polymorphic modification from β- to δ- and in the latter case from ɛ- to β- modifications in the corresponding CACs. The correlations of the Ea values with the square of detonation velocity as a representative of performance and with the heat of combustion as a representative of the energy content are consistent with already previously described relationships of this type, including exceptions for pure nitramines.

Growth, structural, optical, and thermal behavior of bibenzyl organic single crystal for scintillator applications

Growth, structural, optical, and thermal behavior of bibenzyl organic single crystal for scintillator applications

Evaluation of thermal, dielectric and mechanical behavior of 4-nitrophenol crystal

The organic 4-nitrophenol bulk crystal was grown using single wall ampoule with the vertical Bridgman technique. The grown-crystal was analyzed by single-crystal XRD, powder-XRD, proton NMR, and FTIR studies to investigate its various properties. Single-crystal XRD evidenced the monoclinic crystal system with the space group of P21/c. Thermal stability was analyzed using thermogravimetric, differential thermal curves, and kinetic parameters. The dielectric behavior and electrical conductivity were discussed. Vickers micro-hardness tester performed to find the mechanical strength and the hardness tester showed that the 4-nitrophenol crystal obeys the indentation size effect. These results may be used for microelectronics and nonlinear optical device applications.

Ammonium Metatungstate, (NH4)6[H2W12O40]: Crystallization and Thermal Behavior of Various Hydrous Species

Various hydrous ammonium metatungstate phases (NH4)6[H2W12O40]·XH2O (AMT-X) have been obtained in the form of single crystals, using supersaturated solutions, antisolvent crystallization, and partial dehydration as strategies for crystal growth. On the basis of laboratory X-ray diffraction data, the crystal structures of the hydrous phases with X = 22, 12.5, 9.5, 8.5, 6, 4, and 2 as well of the cocrystals with X = 12-ethanol and X = 4-2acetone have been determined for the first time. AMT-22 forms the solid solution series (NH4)6–xKx[H2W12O40]·22H2O with the potassium salt (PMT-22) without a miscibility gap. Its tetragonal crystal structure shows a distorted cubic close-packed arrangement of the spherical α-Keggin-type [H2W12O40]6– anions with disordered ammonium N and water O atoms in the voids. The crystal structures of the other, less-hydrated AMT phases can be derived from distorted hexagonal rod packings of the α-Keggin anions, likewise with the cations and crystal water molecules in the voids. The thermal behavior of AMT-22 crystals reveals a quick dehydration, with AMT-9.5 as an intermediate and AMT-4 as a stable hydrate phase under ambient conditions. Upon further heating, the material decomposes with stepwise formation of AMT-2, AMT-1, AMT-0, and an amorphous phase, before orthorhombic WO3 forms above 400 °C. One of the commercially available AMT phases, “(NH4)6[H2W12O40]·XH2O” (with X = unspecified) has a water content of X = 4 but crystallizes in a structure other than AMT-4. Consequently, the 4-hydrate shows polymorphic behavior.

Luminescence properties of large-size Li2MoO4 single crystal grown by Czochralski method

Large-size Li2MoO4 single crystal was successfully grown by Czochralski method using the polycrystalline Li2MoO4 bulks synthesized via the conventional solid-state reaction. The phase identification, thermal behavior and optical transmission spectra of Li2MoO4 single crystal were studied systematically. The band gap of Li2MoO4 was estimated from the transmission spectra according to Tauc and Menth’s law. The luminescence spectra and decay characteristics under 355 nm laser excitation were investigated in detail. Li2MoO4 single crystal had a wide luminescence peak around 540 nm as a result of intrinsic luminescence emission of tetrahedral MoO42-. The maximal luminescence intensity increased with the ambient temperature cooling down. Meanwhile, the luminescence decay times decreased monotonically with the temperature increasing from 42 K to 298 K.

Investigation of phonon properties and thermal behavior of UO2 crystal using density-functional theory

Understanding thermal behavior and processes underlying the heat transport of UO2 nuclear fuel in nuclear reactor plays a key role in predicting the efficiency of the fuel. If the heat transport, which is an important parameter in temperature distribution of the fuel, does not occur properly, the continuous increase of temperature would lead to the melting of the fuel and therefore, environmental hazards. In this work, by using a non-spin-polarized calculation for the simple description of the paramagnetic state and ignoring the Hubbard correction, the thermal properties and phonon properties of bulk UO2 are calculated. These calculations are based on the density-functional theory (DFT) and density-functional perturbation theory (DFPT). To determine the lattice-vibration properties by the finite-displacement method, we have calculated the second-order and third-order force constants based on which such quantities as constant-volume specific heat, Gruneisen parameter, three-phonon scattering rate, scattering rate due to different levels of isotopic enrichment, and cumulative thermal conductivity are calculated. The results of the calculated specific heat based on the harmonic approximation show a good agreement with the experimental values, specifically for temperatures lower than 400 Kelvin. The results obtained for three-phonon scattering rate reveal that the scattering rate increases with temperature, thereby leading to the decrease of thermal conductivity. The results related to different levels of isotopic enrichments do not show any sensible changes in the scattering rates.

Application of Box-Behnken Design to Investigate the Effect of Process Parameters on the Microparticle Production of Ethenzamide through the Rapid Expansion of the Supercritical Solutions Process.

In this study, the rapid expansion of the supercritical solutions (RESS) process was used to produce microparticles of a commonly used anti-inflammatory drug, ethenzamide. The effects of process parameters in RESS including the extraction temperature, pre-expansion temperature, and post-expansion temperature were investigated using the Box–Behnken design. According to the results of the analysis of variance (ANOVA), the effect of pre-expansion temperature is the most significant parameter on the mean size of RESS-produced ethenzamide. A higher pre-expansion temperature benefits the production of smaller crystals. In addition, a quadratic effect of the post-expansion temperature was also identified. Through RESS, ethenzamide microparticles with a mean size of 1.6 μm were successfully produced. The solid-state properties including the crystal habit, crystal form, thermal behavior, and spectrometric property were characterized by scanning electron microscopy (SEM), Fourier-transform infrared spectrometer (FTIR), differential scanning calorimeter (DSC), and powder X-ray diffraction (PXRD). These analytical results show that the rod-like crystals were generated through RESS, and the crystal form, thermal behavior, and spectrometric property of RESS-produced crystals are consistent with the unprocessed ethenzamide.

Investigation on thermal behaviour and optical properties of non-symmetric cholesterol-based twin liquid crystals with thioester linkages

ABSTRACT Herein, a series of novel asymmetric cholesterol-based liquid crystal compounds containing thioester linkage and an analogue containing carboxylate linking unit have been synthesised and characterised. Thermal analyses demonstrated that all desired target compounds possess broad mesophase temperature ranges (ΔT, 91–142.5°C) and high thermal stability (clearing points, 214.9–259.4°C). Due to the increasing chain length of the inner flexible spacer, clearing points and entropy changes (ΔS/R) of the COS-containing dimers showed pronounced parity effects. All dimers exhibited enantiotropic mesophase behaviour with an SmC* phase and a typical cholesteric phase (N*), which were validated by XRD and POM. The effect of structural changes of COO and COS unit in the linking group on the mesomorphic properties was analysed. Comparing C6SAR with C6OAR, it was found that the thioester-containing dimer exhibited more stable mesophase, higher phase transition temperatures (about 20°C higher) and enthalpy values (ΔH). All final products exhibited selective reflection to visible light, produced multiple colours. The higher temperatures led to the shorter pitch, which can further result in shorter reflection wavelengths, and the ‘blue shift’ occurred.

Synthesis, crystal structure, photoluminescence, thermal, laser damage threshold and DFT calculations of 1,10-phenanthrolinium-2-carboxy-6-nitrobenzoate

Single crystals of 1, 10-Phenanthrolinium-2-carboxy-6-nitrobenzoate (PCNB) were grown by slow solvent evaporation solution growth method from methanol at room temperature. The various functional groups present in the molecule are identified by FT-IR analysis. UV–Vis–NIR spectral studies reveal that the title crystal is transparent in the wavelength region of 300–1200 nm. The presence of different protons and carbon atoms of the grown salt was ascertained by 1H and 13C NMR analyses. Single crystal X-ray diffraction data indicate that the title crystallizes in the monoclinic crystal system with space group P21/c. Thermogravimetric (TG) and Differential Thermal Analysis (DTA) were carried out to characterise the thermal behavior and stability of PCNB crystal. Mechanical behavior of PCNB was studied by Vickers's microhardness test. Dielectric studies reveal that dielectric constant and dielectric loss decrease with increasing frequency and become almost a constant at higher frequencies for all temperatures. Quantum chemical calculations have been performed through DFT method at 6–311++G (d,p) level of theory. Natural bond orbital (NBO) calculations were employed to study the stabilities arising from charge delocalization and intermolecular interactions of PCNB crystal. The atomic charge distributions of the various atoms present in PCNB are obtained by Mulliken charge population analysis.

Crystal Structure and Strong Piezoelectricity of New Amino Acid Based Hybrid Crystals: [H-β-(3-Pyridyl)-Ala-OH][ClO4] and [H-β-(4-Pyridyl)-Ala-OH][ClO4

The new amino acid based [H-β-(3-pyridyl)-Ala-OH][ClO4] and [H-β-(4-pyridyl)-Ala-OH][ClO4] crystals were synthesized, and their structure and functional piezoelectric properties were investigated in detail. Both analogs crystallize in the polar, piezoelectric P21 space group. Piezoresponse force microscopy (PFM) measurements revealed that shear piezoelectric coefficient of [H-β-(3-Pyridyl)-Ala-OH][ClO4] crystal is more than twice that in the widely used transducer material lithium niobate, LiNbO3. The crystal structures of both perchlorate derivatives were determined, and the influence of the inter- and intramolecular hydrogen bond network on piezoelectricity of crystals were discussed. The existence of the intramolecular hydrogen bonding was confirmed by means of IR spectroscopy measurements. Thermogravimetric (TGA) technique was applied to study the thermal behavior of title crystals.

Growth and investigation on structural optical, thermal and magnetic behavior of ammonium bisulphate nonlinear single crystals

Abstract The new inorganic NLO ammonium bisulphate single crystal was synthesized by the slow evaporation method. The structure of the grown crystal was analyzed by X-RAY diffraction studies. The FT-IR spectrum confirms the presence of different functional groups of the grown crystal. Its optical transmittance is understood by UV-Vis-NIR spectrophotometer. The presence of SHG efficiency of the grown crystal was confirmed by Kurtz powder technique. The dissever nature of the crystal was analyzed by thermal studies. The mechanical behavior of the grown crystal is carried out at room temperature using Vicker's micro hardness tester, whenever the load increased, its hardness also increased. The elemental composition of the grown crystal was studied by EDAX analysis. The paramagnetic behavior of the grown crystal is confirmed by vibrating sample magnetometer.

Anisotropic electrical and optical studies of organic biphenyl single crystal grown by modified Czochralski technique

Czochralski growth technique was used to grow organic single crystal of biphenyl along direction. The problems of excessive evaporation due to high vapour pressure and low melting point in BP was overcome by suitable modifications in the CZ set up. The monoclinic symmetry with space group P21/c for the grown crystal was confirmed by powder as well as single crystal X-ray diffraction. Intermolecular interactions present in the grown single crystal were analysed by Hirshfeld surface and 2-dimensional fingerprint plot. The biphenyl crystal (size 8 × 5 × 1.8 mm3) showed a transparency of 39% along and 3% along directions with a lower cut off wavelength of 311 nm and 307 nm, respectively. Photoluminescence emission peaks were observed at 494 nm and 488 nm in the two directions. Appreciable change in the dielectric constant (~ 56–~ 114) was observed along these two directions at RT which were frequency independent. The functional groups and thermal behaviour of BP crystals were also reported. Mechanical behaviour was explained with the help of void study and indentation technique. The anisotropic electrical and optical behaviour of BP can be used to fabricate devices with tunable output.

Temperature dependence of luminescence properties in Li2WO4 single crystal grown by Bridgman method

Transparent Li2WO4 single crystal was grown by vertical Bridgman method. The phase identification, Fourier transform infrared spectra, thermal behavior, and optical transmission spectra of Li2WO4 crystal had been studied in detail. The luminescence properties as a function of temperature were investigated systematically. The transmissivity of as-polished crystal samples with the thickness of 2.0 mm, 4.0 mm, and 6.0 mm reached 85–89%, 81–85%, and 78–81% in 400–800 nm wavelength range, respectively. Li2WO4 crystal has wide luminescence peaks around 626 nm, 574 nm, and 543 nm at the ambient temperature of 30 K, 50 K, and 75 K, respectively. The luminescence peaks are ascribed to the intrinsic luminescence emission of tetrahedral [WO4]2-. The emission line width presents an obvious broadening with the increasing temperature. The maximal luminescence intensity increases with the ambient temperatures cooling down. The luminescence decay times monotonically decrease with the temperature increasing in temperature range of 30–75 K. The decay times at 30 K, 50 K, and 75 K correspond to 97.92 μs, 30.16 μs, and 1.97 μs, respectively, while maintain a constant around 1.80 μs in 75–300 K.

Crystal growth, Dielectric and Thermal Studies on N-Methyl-4-Nitroaniline: Isophthalic Acid Molecular Adduct Crystals

Organic compound N-methyl-4-nitroaniline isophthalic acid (NMNAIPA) needle shaped single crystals with a dimension of 4x1x1 cm3 were grown by slow evaporation technique in methanol as solvent at ambient temperature. The grown single crystals have been analyzed through powder X-ray diffraction (XRD), proton nuclear magnetic resonance (1HNMR), carbon NMR (13CNMR), Fourier transform infrared (FT-IR), Raman spectra and UV-Vis spectra. Based on powder XRD patterns, the as-grown NMNAIPA single crystal was a good crystalline in nature. The various planes of reflection have been identified from the powder XRD pattern. It belongs to the monoclinic crystal system. The presences of functional groups were identified from FT-IR and Raman spectra. UV-Vis-NIR spectral analysis showed 74% transmission in the visible region for NMNAIPA crystal. The dielectric constant and dielectric loss of the as-grown NMNAIPA single crystal was studied as a function of frequency and temperature. Thermo gravimetric (TG) and differential scanning calorimetric (DSC) techniques were carried out to characterize the thermal behavior and stability of as-grown NMNAIPA single crystal. It has thermal stability around 421 K. The nonlinear optical (NLO) activity test using a pulsed Nd:YAG laser confirms the generation of second harmonics and it shows 1.25 times relatively greater than KDP.

Crystal growth, Dielectric and Thermal Studies on N-Methyl-4-Nitroaniline: Isophthalic Acid Molecular Adduct Crystals

Organic compound N-methyl-4-nitroaniline isophthalic acid (NMNAIPA) needle shaped single crystals with a dimension of 4x1x1 cm3 were grown by slow evaporation technique in methanol as solvent at ambient temperature. The grown single crystals have been analyzed through powder X-ray diffraction (XRD), proton nuclear magnetic resonance (1HNMR), carbon NMR (13CNMR), Fourier transform infrared (FT-IR), Raman spectra and UV-Vis spectra. Based on powder XRD patterns, the as-grown NMNAIPA single crystal was a good crystalline in nature. The various planes of reflection have been identified from the powder XRD pattern. It belongs to the monoclinic crystal system. The presences of functional groups were identified from FT-IR and Raman spectra. UV-Vis-NIR spectral analysis showed 74% transmission in the visible region for NMNAIPA crystal. The dielectric constant and dielectric loss of the as-grown NMNAIPA single crystal was studied as a function of frequency and temperature. Thermo gravimetric (TG) and differential scanning calorimetric (DSC) techniques were carried out to characterize the thermal behavior and stability of as-grown NMNAIPA single crystal. It has thermal stability around 421 K. The nonlinear optical (NLO) activity test using a pulsed Nd:YAG laser confirms the generation of second harmonics and it shows 1.25 times relatively greater than KDP.

Crystallographic, Thermal and Hirshfeld Surface Studies of N-(1H-1,3-benzodiazol-2-yl)benzamide

In present study, the compound N-(1H-1,3-benzodiazol-2-yl)benzamide was synthesized and characterized by 1H NMR, IR, elemental and X-ray analysis. A good quality single crystal was grown by slow evaporation solution growth technique to investigate their X-ray structure. The compound crystallizes in a triclinic crystal system with space group P-1 and having the unit cell parameters of a = 10.2350(5) Ǻ, b = 14.7494(7) Ǻ, c = 24.2813(11) Ǻ, α = 79.084(4) °, β = 83.927(4) °, γ = 80.039(4) °, V = 3534.8(3) A3 and Z = 12. The molecules are arranged in a linear manner and crystal packing is stabilized by N–H···O, N–H···N, C–H···O, C–H···π and π–π intermolecular interactions. These interactions generate various hydrogen bond patterns e.g. $$ {\mathbf{R}}_{{\mathbf{2}}}^{{\mathbf{1}}} ({\mathbf{6}}) $$ , $$ {\mathbf{R}}_{{\mathbf{2}}}^{{\mathbf{2}}} ({\mathbf{10}}) $$ , $$ {\mathbf{R}}_{{\mathbf{2}}}^{{\mathbf{2}}} ({\mathbf{8}}) $$ , $$ {\mathbf{R}}_{{\mathbf{2}}}^{{\mathbf{1}}} ({\mathbf{7}}) $$ and $$ {\mathbf{R}}_{{\mathbf{4}}}^{{\mathbf{4}}} ({\mathbf{30}}) $$ . Hirshfeld surface analysis suggests that the intermolecular H···H, C···H, N···H and O···H contacts are predominant. The thermal behavior of crystal was determined by DSC and TGA analysis.

Crystal growth and properties of novel organic nonlinear optical crystals of 4-Nitrophenol urea

Single crystals of 4-Nitrophenol urea have been grown from water using slow evaporation technique at constant temperature, with the vision to improve the properties of the crystals. The unit cell parameters of the grown crystals were determined by single crystal and powder X-Ray diffraction. FTIR studies reveals the presence of different vibrational bands. The Optical studies confirmed that the crystal is transparent up to 360 nm .TGA and DSC studies were carried out to understand the thermal behavior of crystals. The SHG studies show the suitability of the crystals for NLO applications. The etching studies were carried out to study the behavior of the crystals under different conditions.These studies reveal that the crystals of 4-Nitrophenol urea are suitable for device applications.