- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Growth and study of nonlinear optical P-dimethyl-aminobenzaldehyde crystal for photonic device application
摘要： Pera dimethyl-aminobenzaldehyde (p-DMAB) is a well known aromatic compound with nonlinear optical (NLO) properties in various application fields such as optoelectronics, photonics etc. The single crystal of p-DMAB is grown by slow evaporation technique (Constant Temperature Bath) at room temperature. These grown crystals are good in size with transparent appearance. The grown crystals are characterized using XRD, FTIR spectroscopy, Elemental analysis, UV-Spectroscopy, Second Harmonic Generation (SHG), Optical limiter behaviour, Photoluminescence (PL), Vickers hardness, Scanning Electron Microscopy (SEM). Single crystal XRD provides information about the crystal structure. The powder XRD shows that material is crystalline in nature. FTIR- Spectroscopy provides information about the relevant functional group present in the compound. CHN (Carbon-Hydrogen-Nitrogen) analysis shows appropriate composition of these elements within this material. UV-Vis study reveals that materials have wide window over the entire visible region. The observed order of refractive index points their use in anti-refracting coating devices. Good linear polarisability, susceptibility, optical conductivity data are also appropriate to decide their use in optical device fabrications. Wider optical band gap described dielectric behavior of material. Second harmonic generation test shows that material has 2.03 times greater efficiency than the reference material KDP. Moreover the emission of green light indicates that the material can be used to develop green-blue laser. Optical limiter behavior shows that material is suitable for fabrication of an optical limiter device. In PL study desecrate energy level indicates purity of grown crystals. The Vicker’s micro hardness study was also carried out on the sample. Vickers hardness test shows increment in hardness, yield strength and stiffness of material. SEM images show smooth morphology at different magnifications.
关键词： FTIR,Crystal growth,SEM,XRD,Vickers hardness,CTB method
更新于2025-09-23 15:22:29
-
Electrical Transport Properties of Thin Film Composed of a-ZnO Nanorods
摘要： Background: Due to its wide band gap, high exciton binding energy and high breakdown strength, the nanostructures of ZnO may find applications for electronic, photonic devices, and high-frequency applications. Objective: The aim of the present work is to study electrical transport of thin film composed of a-ZnO nanorods. Method: Physical vapour condensation method was employed to fabricate the nanorods of ZnO. The morphology of these nanorods was investigated with the help of scanning electron microscope. X-ray diffraction pattern of as-prepared thin film was recorded using X-ray diffractometer. For dc conductivity measurements, four-probe method was used. Result: The as-prepared ZnO nanorods have diameter ranging from 10-20 nm and the length is of order of few hundred nanometers. XRD pattern of film composed of ZnO nanorods suggests the amorphous nature. Temperature dependence of dc conductivity has been studied over the temperature range of (297- 4.2K). For the temperature range of 297-120K, Mott’s three dimensional variable range hopping (VRH) is applied to explain the electrical conduction. For lower temperature range (120 - 4.2K), 2D-variable-range hopping in localized states near the Fermi level may be responsible for the transport of carriers. Conclusion: Variable range hopping mechanism (VRH) has been suggested for the entire temperature range (298-4.2K) on the basis of temperature dependence of dc conductivity data, which changes from 3D to 2D on moving to lower temperatures side (below 125K).
关键词： physical vapour condensation technique,variable range hopping,XRD,ZnO nanorods,SEM,Mott’s parameters,electrical conduction mechanism
更新于2025-09-23 15:22:29
-
Prospective scintillation electron detectors for S(T)EM based on garnet film scintillators
摘要： The performance of a scintillation electron detector for a scanning electron microscope and/or a scanning transmission electron microscope (S(T)EM) based on new epitaxial garnet film scintillators was explored. The LuGAGG:Ce and LuGAGG:Ce,Mg film scintillators with chemical formula (Ce0.01Lu0.27Gd0.74)3–wMgw(Ga2.48Al2.46)O12 were prepared and their cathodoluminescence (CL) and optical properties were studied and compared with the properties of current standard bulk single crystal YAG:Ce and YAP:Ce scintillators. More specifically, CL decay characteristics, CL emission spectra, CL intensities, optical absorption coefficients, and the refractive indices of the mentioned scintillators were measured. Furthermore, electron interaction volumes with absorbed energy distributions, photomultiplier (PMT) photocathode matchings, modulation transfer functions (MTF), and the photon transport efficiencies of scintillation detectors with the mentioned scintillators were calculated. A CL decay time for the LuGAGG:Ce,Mg film scintillator as low as 28 ns with an afterglow of only 0.02% at 1 μs after the e-beam excitation was observed. As determined from calculated MTFs, the scintillation detectors with the new film scintillators lose contrast transfer ability above 0.6 lp/pixel, while the currently commonly used YAG:Ce single crystal scintillators already do so above 0.1 lp/pixel. It was also calculated that the new studied film scintillators have an 8% higher photon transfer efficiency, even for a simple disk shape compared with the standard bulk single crystal YAG:Ce scintillator. The studied LuGAGG:Ce,Mg epitaxial garnet film scintillators were evaluated as prospective fast scintillators for electron detectors, not only in S(T)EM but also in other e-beam devices.
关键词： electron detector,multicomponent garnet film,scintillator,STEM,SEM,LuGAGG:Ce,Mg,cathodoluminescence
更新于2025-09-23 15:22:29
-
The influence of yttrium-ions on the optical and electrical behavior of PVA polymeric films
摘要： The polyvinyl alcohol (PVA) films doped with various wt% of yttrium nitrate salt were synthesized by standard solution casting technique in order to examine the functional electrical and optical properties. The degree of the crystalline structure that evaluated in the films were investigated by x-ray diffraction and Fourier transform infrared spectroscopy measurements. In addition, the surface images have been obtained via scanning electron microscopy (SEM). The optical parameters have been calculated from UV–visible-NIR transmittance spectroscopy. Also, the dielectric constant measurement and the DC resistance that are arisen in the PVA films with different wt% of Y3+ have been done. All the samples show semi-crystalline phases. The average size, of the cluster Y3+ in the SEM images, increase to 1.63 μm for PVA/37 wt% Y3+ sample. Therefore, the optical absorption of this sample is higher than the others. The value of the energy gap decrease from 5.11 eV to 4.47 eV for PVA/0.037 wt% Y3+ and PVA/37 wt% Y3+ samples, respectively. The nonlinear current—voltage behavior, at high applied voltage, of the polymeric films, is observed with different values of slope, which is a characteristic of the varistor materials. So, these films could be used in different applications like optoelectronic and varistor devices.
关键词： Varistor,Dielectric,XRD/FTIR,SEM,Optical energy gap,Y3+-doped PVA
更新于2025-09-23 15:22:29
-
Effective SEM Analytical Techniques for the Cathodoluminescence Visualization of Intergranular Cements in Saint Peter Sandstone: A Round Robin Exercise
摘要： The use of Cathodoluminescence (CL) as an analytical tool for geoscience and materials research is well established. Many minerals exhibit CL when activated by the high-energy electron beam bombardment of the Scanning Electron Microscope (SEM) [1]. CL imaging capabilities vary among laboratories due to the differences in detector type, sample preparation (epoxy, polish, coating), SEM type (W, LaB6, FE) and analytical conditions (kV, pA/nA, sample temperature). An interlaboratory comparison was initiated to assess the optimal conditions for obtaining high resolution CL imagery [2]. Quartz (and its polymorphs) are often difficult to image by CL due to low CL response and thus it was chosen as a test material. Composed of fine to medium-grained silicon dioxide, St. Peter Sandstone is used extensively as a proppant in hydraulic formation fracture (fracking) [3]. Appropriate sample preparation is necessary for optimal CL imaging results, varying from lab to lab. In the case of the porous St. Peter Sandstone with incomplete and fragile intergranular cement structures, producing a polished sample surface without plucking grains and removing the cements is imperative. For this interlaboratory comparison, polished samples were prepared from a single St. Peter Sandstone sample that was cored perpendicular to the bedding. Samples were imbedded in Epoxy and polished to a sub micron finish. Six of these samples were shared with other SEM-EPMA laboratories with the goal of refining SEM-CL conventions for cement study and imagery. As of abstract deadline time, we have 3 examples of CL images to present, and expect to have others by the M&M conference.
关键词： intergranular cements,SEM,quartz,St. Peter Sandstone,Cathodoluminescence
更新于2025-09-23 15:21:21
-
Effect of Magnesium Substitution on the Structural, Morphological, Optical and Wettability properties of Cobalt Ferrite Thin Films
摘要： Cobalt ferrite thin films with magnesium substitution (Co1-xMgxFe2O4 for 0.0 ≤ x ≤ 1.0) were grown on clean glass substrate with dimensions (75 mm × 25 mm × 1.45 mm) using spray pyrolysis method. The grown thin films were annealed at 500°C for 4 h and further used for structural, morphological, optical and surface wettability investigations. The structural characterizations of the prepared films were performed through X-ray diffraction (XRD) technique at room temperature. The analysis of the XRD pattern shows the formation of single phase cubic spinel structure of the films. The most intense peak (311) of the XRD pattern was used to estimate the average crystallite size. The obtained crystallite size varies between 16 nm to 19 nm confirming the nanocrystalline nature of the films. The lattice constant calculated from XRD data show decreasing nature from 8.386 ? to 8.365 ? with increase in magnesium content x. The variation of X-ray density with magnesium content x shows initial increasing nature and then decreasing nature. Metal cation active vibration modes, metal oxygen stretching and bending vibrations were confirmed through the Raman analysis. Surface morphology of the films was studied by using scanning and transmission electron microscopy (SEM and TEM) technique. Observations of SEM micrographs reveal that particles are in nanosize dimensions and almost distributed uniformly. Particle size calculated from TEM analysis was found to be in the range of 5-18 nm. The band gap of the films was measured by UV-VIS spectrophotometer. It is observed that, the energy band gap decrease from 2.83 eV to 2.37 eV as increase in magnesium substitution. The Photoluminescence study showed the characteristic near-band-edge emission of presently investigated films samples at around 710 nm. The contact angle measurements revealed the hydrophilic nature of all the thin films under investigation.
关键词： CoFe2O4,spray pyrolysis,SEM-TEM,thin films,Mg2+ substitution,PL
更新于2025-09-23 15:21:21
-
Dielectric and piezoelectric properties of Sm3+ doped lead barium niobate (PBN) ceramics
摘要： Rhombohedral samarium doped Lead based ceramic materials were fabricated by a high temperature conventional solid state mixed oxide ceramic process. The ceramic composition Pb1-x-3y/2Bax Re3+ y Nb2O6 (x = 0.35 and y=0.00, 0.02, 0.04 and 0.06, Re3+ = Sm3+). The pure and Sm3+ doped lead barium niobate ceramic materials are single phase with rhombohedral(hexagonal) symmetry obtained from powder x-ray diffraction (XRD). The grain size has been measured for all the compositions and lying between 1.60-2.90μm. Broad dielectric peak phase transitions observed with temperature in pure and Sm3+ ion modified lead barium niobate ceramic materials. It is observed that the high values of piezoelectric charge coefficients in d31 and d33 in Sm3+ doped lead barium niobate ceramics. The mechanical quality factor Qm and d33 increases with increase of Sm3+ ion concentration and indicating a highly polarisable lead ion contributing to high Curie temperature dielectric constant.
关键词： SEM,Piezoelectric properties,Rhombohedral,Synthesis of ceramic compositions,dielectric,X-Ray diffraction
更新于2025-09-23 15:21:21
-
Electrical and Electromagnetic Interference (EMI) shielding properties of hexagonal boron nitride nanoparticles reinforced polyvinylidene fluoride nanocomposite films
摘要： The hexagonal boron nitride nanoparticles (h-BNNPs) reinforced flexible polyvinylidene fluoride (PVDF) nanocomposite films were prepared via a simple and versatile solution casting method. The morphological, thermal and electrical properties of h-BNNPs/PVDF nanocomposite films were elucidated. The electromagnetic interference (EMI) shielding properties of prepared nanocomposite films were investigated in the X-band frequency regime (8–12 GHz). The EMI shielding effectiveness (SE) was increased from 1 dB for the PVDF film to 11.21 dB for the h-BNNPs/PVDF nanocomposite film containing 25 wt% h-BNNPs loading. The results suggest that h-BNNPs/PVDF nanocomposite films can be used as lightweight and low-cost EMI shielding materials.
关键词： Hexagonal boron nitride,PVDF,SEM,EMI shielding,DSC,electrical properties
更新于2025-09-23 15:21:21
-
Structural, Electrical and Morphological Properties of Materials Type Sillenite Phase Bi12TiO20
摘要： This work reports the investigation of the ternary system Bi2O3–TiO2–MgO. Some compositions have been synthesized by solid state reaction at 800?°C and characterized by powder X-ray diffraction. The doping of (α-Bi2O3) allowed us to stabilize three compositions isotype of sillenite structure phase with formulas Bi0.9 Ti0.1 O1.55, Bi0,9 Ti0,05Mg0,05 O1,5, and Bi0.8 Mg0.1 Ti0.1 O1.5. The structural resolution of the synthesized materials was performed using Rietveld method by means of FullProf program. It crystallizes in the cubic system. The space group I23 and lattice parameter a = 10.1723(2) ?. The morphological proprieties of the synthesized compositions have been investigated by means of scanning electron microscopy (SEM). Sintered samples showed a dense and uniform microstructure. The density of sintered samples obtained is nearly 92% of the theoretical density. Various impedance model including capacity and Warburg impedances have been used to interpret the Nyquist representations of electrical analyses. The highest conductivity is observed for Bi0.9 Ti0.1 O1.55 (σ = 1.39E?07 at 600?°C).
关键词： Electrical Impedance,SEM,Spectroscopy,X-ray diffraction,Sillenite
更新于2025-09-23 15:21:21
-
Multipulse laser ablation of BiSn eutectic: Noncongruent element transfer and morphology analysis
摘要： The surface of a eutectic BiSn target was ablated by several series of pulses at different spots using an excimer laser with a wavelength of 351 nm and a pulse duration of 20 ns. Morphology of ablation craters formed under a different number of pulses was analyzed with a scanning electron microscope, an optical profilometer, and an energy dispersion spectroscope (EDS). Laser-induced breakdown spectroscopy (LIBS) measurements were taken for each crater with the last pulse in the series of pulses. The ratio of peak intensities (Bi I peak at 472.25 nm and Sn I 563.16 nm) of LIBS spectra for craters formed by different series of pulses decreased from maximum at a single pulse to a stable magnitude after a series of 70 pulses. EDS mapping of crater areas for different series of pulses shows a decrease in Bi atoms abundance, in correlation with the decrease in normalized intensity of Bi peak LIBS spectra. The change of the chemical composition in the ablation area is explained based on the Knudsen evaporation model. For the first time, pronounced hydrodynamic effects resulting in the formation of 50 μm-high rims were observed. The unusual morphology of the ablated area is explained on the basis of hydrodynamic effects and recoil pressure.
关键词： LIBS,BiSn eutectic,laser ablation,EDS,SEM
更新于2025-09-23 15:21:01