Papers by Keyword: Inorganic Compounds

Abstract: The high-pressure torsion (HPT) method, which is currently used as a severe plastic deformation process to develop advanced structural and functional materials, was first introduced to the public by Bridgman in 1935 as a tool to investigate the mechanism of deep-seated earthquakes. The HPT method was recently introduced as a new platform to simulate astronomical impacts on a miniature scale. Frequent impacts by small solar system bodies (meteoroids, asteroids and comets) about four billion years ago are considered a possible pathway for the delivery or synthesis of essential biomolecules required for life on the Earth. The application of HPT to glycine amino acid led to new justifications for some astronomical phenomena reported in comets or on the Earth such as the formation of alcohol. The extension of this application also led to the introduction of inorganic-biomolecule composites as new functional materials with good biocompatibility.

Abstract: CdSiO₃: Mn²⁺, Er³⁺ long-lasting phosphor was prepared by the conventional high temperature solid-state method. Effects of the concentration of Mn²⁺ and Er³⁺ on the luminescent properties of phosphor CdSiO₃: Mn²⁺, Er³⁺ were investigated by means of photoluminescence (PL) spectra and the afterglow intensity decay curves. It was found that when the Mn²⁺ and Er³⁺ dopant-concentrations were 0.2 mol% and 0.8 mol% of Cd²⁺ ions in CdSiO₃, respectively, the luminescence of phosphor prepared had better luminescent property and longer afterglow time. The phosphorescence for it could be seen with the naked eye for more than 60 min in the dark after the removal of the 254 nm UV light. Role of Er³⁺ co-doped into CdSiO₃: Mn²⁺ matrix was discussed in this paper.

Abstract: Carbon nanotubes (CNTs) were dispersed in aqueous solution with the inorganic compounds (H₃O₄₀PW₁₂ and H₃BO₃) by ultrasonic agitation. The dependency relationship between the inorganic solution concentration and CNTs dispersity was investigated by spectrophotometry. The results show that H₃O₄₀PW₁₂ and H₃BO₃ can promote CNTs dispersion in aqueous solution. CNTs disperse very well in the appropriate concentration. The optimal concentration of H₃O₄₀PW₁₂ solution is 2mg/mL, and the optimal concentration of H₃BO₃ solution is 4mg/mL. CNTs static stability in H₃BO₃ solution is better than that in H₃O₄₀PW₁₂. CNTs can still keep good dispersity in H₃O₄₀PW₁₂ solution under high speed centrifugation. The strong adsorption effect between CNTs surface and inorganic compound induces the dispersive stability of CNTs in aqueous solution.

Abstract: The SrSO₄ spherical aggregates with hierarchical architecture was fabricated by using Sr(NO₃)₂ react with Na₂SO₄ aqueous solution under ambient conditions at room temperature. The SrSO₄ spherical aggregates have a uniform diameter of about 10μm, which are composed of numerous well-aligned single tablet-like SrSO₄ crystalline oriented radially to their centre. The phase structure, microstructure and luminescence properties were characterized by XRD, SEM, PL and DRS, respectively.

Abstract: Manganese doped alpha-lithium iodate have been synthesized and single crystals have been grown for nonlinear optical applications. The grown crystal has been subjected to single crystal X-ray diffraction to confirm the structure. The crystalline perfection was assessed by high-resolution X- ray diffractometer (HRXRD). Second harmonic generation (SHG) efficiency was found to be 71 times than that of KDP. The UV–Vis-NIR spectroscopic study revealed that the grown crystal has good optical transparency in the visible region clearly indicates that Mn doped α-LiIO₃ crystals can be used as window material in optical instruments. Presence of dopant was confirmed by energy-dispersive spectrometry.

Abstract: Hexagonal-phase LaF3: Ce3+, Pr3+, and Sm3+ doped (LCPS) nano-crystals have been synthesized by keeping same molarities of rare earth elements using aqueous route. The samples have been synthesized in conventional microwave on low power range in about an hour’s time. The phase formation has been verified by powder X-ray diffraction (XRD).Hexagonal geometry of the LCPS nano-crystals has been observed with an average particle size of 20 nm by TEM analysis. The JCPDS Card No. (32-0483) and selected area electron diffraction (SAED) pattern has been used for identification of crystal structure. The UV- VIS spectra indicated band gap of 5.00eV. The FTIR spectrums have been used for assignment of fundamental vibrations. Blue fluorescence observed with exciting wavelengths of 254 nm respectively. The presence of rare-earth elements in LCPS nano-crystals have been verified by the EDAX spectra.

Abstract: A series of yttrium-doped lithium trivanadates LiV_3-yY_yO₈ (y=0, 0.01, 0.03, 0.05, 0.1 and 0.2) were synthesized by a solid-state reaction. X-ray diffraction (XRD) tests show that a proper amount of yttrium doping in LiV₃O₈ can modify its structure. Charge-discharge tests show that doped samples with a proper amount of yttrium display good cycling stability compared with undoped sample. The cyclic voltammetry (CV) tests indicate that the proper amount of yttrium doping in LiV₃O₈ can stabilize its original structure. Yttrium doping is a convenient and effective method for improving the electrochemical performances of LiV₃O₈.

Abstract: Co-doped ZnO nanorods membrane was deposited at glass substrate in a simple chemical water bath. The morphology and crystal structure of the samples were characterized by SEM, TEM and XRD. It is shown that the ZnO rods membrane exhibits an excellent orientation along the c axis. X-ray diffraction study also indicates decrease in the lattice parameter after Co doping. The results of EDS and XPS verify that Co²⁺ is successfully doped into the lattice of nano ZnO rods. 2at% and 5at% Co doped ZnO rods behave stronger UV emission and weaker visible emission.

Abstract: Zn and Cu were separately incorporated to the diamond powder and then the compacts were prepared under 5GPa, 1273K. The results showed that Zn was a good additive to prepare polycrystalline diamond by high-pressure and high-temperature (HPHT) because it could inhibit the graphitization of diamond. The element Zn left in the polycrystalline was in the form of ZnO. The photoluminescence spectroscopy showed that there were a series of sharp bands between 310 and 390nm when the excitation was above 200nm. However, the full width at half maximum of the diamond peaks mostly was below 0.5nm. The intensity of sharp band decreased with the decrease of excitation energy and then disappeared at last.

Abstract: In this paper, TiO2 nanopowders are produced by gas-phase detonation method. The powders are analyzed by X-ray diffraction (XRD), transmission electron microscopy (TEM) and specific surface area determination. The results indicate that the powders are mixed crystal of rutile and anatase, and have good dispersibility and high specific surface area. Also, the particle sizes of powders are between 40 to 200 nm which are spheroid and cube. The measurement data of detonation pressures shows that the reaction took place under a deflagration to detonation transition (DDT).