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Physical, structural and optical properties of Sm3+ doped lithium zinc alumino borate glasses
摘要： Sm3+ doped lithium zinc alumino borate glasses with composition 15ZnF2–12Li2CO3–10BaO–8Al2O3–(55-x) B2O3–xSm2O3 where x = 0.1, 0.3, 0.5, 0.7 and 1.1 mol% were prepared by conventional melt quenching technique Their optical, physical, structural, mechanical and luminescence properties are investigated. UV–Vis-NIR absorption spectra showed all possible transitions of samarium ion in this glass matrix. Band gap values for all the glass samples were above 3 eV con?rming the insulating nature for the glass. Densities, assessed using the Archimedes rule, were observed to be increasing with increasing samarium concentration. Increase in molar volume with addition of samarium content indicated that the extension of glass network is on account of the increase of number of Non-Bridging Oxygens created by network modi?er samarium ions. Scanning Electron Microscopy (SEM) image showed a smooth surface for the synthezied glass. X-Ray Di?raction (XRD) technique was employed to verify the amorphous nature of the glasses. A Makishima and Mackenzie theoretical model gave acceptable approximation of elasticity constants viz. Young's modulus, shear modulus, bulk modulus and Poisson's ratio. The high Vickers hardness values evaluated with mechanical loads of 50, 100, 300, 500, 1000 g force, proved the stability of the glasses. Emission spectra showed a prominent transition 4G5/2 → 6H7/2 at 598 nm excited with 6H5/2 → 4P3/2 transition at 401 nm. Luminescence quenching e?ect was observed beyond 0.3 mol% Sm2O3 addition. The chromaticity coordinates (x, y) clustered in the orange-red region, making these Sm3+ doped lithium zinc alumino borate glasses suitable candidate for applications in LEDs and solid-state lasers.
关键词： XRD,Photoluminescence,Samarium,Vickers hardness,Radiation shielding,Makishima and Mackenzie,Rare earth
更新于2025-11-21 11:18:25
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Elasticity, Hardness, and Fracture Toughness of Sodium Aluminoborosilicate Glasses
摘要： Due to an increasing demand for oxide glasses with a better mechanical performance, there is a need to improve our understanding of the composition-structure-mechanical property relations in these brittle materials. At present, some properties such as Young’s modulus can to a large extent be predicted based on the chemical composition, while others – in particular fracture-related properties – are typically optimized based on a trial-and-error approach. In this work, we study the mechanical properties of a series of twenty glasses in the quartenary Na2O-Al2O3-B2O3-SiO2 system with fixed soda content, thus accessing different structural domains. Ultrasonic echography is used to determine the elastic moduli and Poisson’s ratio, while Vickers indentation is used to determine hardness. Furthermore, the single-edge precracked beam (SEPB) method is used to estimate the fracture toughness (KIc) for some compositions of interest. The compositional evolutions of Vickers hardness and Young’s modulus are in good agreement with those predicted from models based on bond constraint density and strength. Although there is a larger deviation, the overall compositional trend in KIc can also be predicted by a model based on the strength of the bonds assumed to be involved in the fracture process.
关键词： Vickers hardness,fracture toughness,glass properties,Elastic moduli,crack path
更新于2025-09-23 15:22:29
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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