N. S. Kokode; V. R. Panse; S. J. Dhoble
Abstract
In present work we studied the luminescence properties of Tb 3+ and Mn 2+ doped Ca2PO4Cl phosphor synthesized by wet chemical method were studied with extra heat treatment, to understand the mechanism of excitation and the corresponding emission of prepared phosphor. For the green emission, Tb 3+ ion ...
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In present work we studied the luminescence properties of Tb 3+ and Mn 2+ doped Ca2PO4Cl phosphor synthesized by wet chemical method were studied with extra heat treatment, to understand the mechanism of excitation and the corresponding emission of prepared phosphor. For the green emission, Tb 3+ ion is used as an activator, the excitation and emission spectra indicate that this phosphor can be effectively excited by 380 nm, to exhibit bright green emission centered at 545 nm corresponding to the f→f transition of Tb 3+ ions. The emission spectrum of Mn 2+ ion at 405 nm excitation 4 T1(4G) - 6 A1(6S) gives an emission band at 591 nm (orange-red). The observed photoluminescence (PL) measurements of Tb 3+ and Mn 2+ activated prepared phosphor indicates that these are the outstanding green and orange-red emitting potential phosphor , suitable application for the solid state lighting. The synthesized phosphors were analyzed by X-ray diffraction (XRD) for confirmation of phase and purity. The morphology and structure were characterized by scanning electron microscopy. Thus the phosphors in this system may be chosen as the green component for the tri-color lamp and certainly applied in w-UV LEDs. In the view of the excitation band and excellent luminescent properties, Ca2PO4Cl:Tb 3+ and Mn 2+ phosphor is expected to be a potential candidate for application in n-UV white LEDs and solid-state lighting because of its cost-efficient manufacturing, mercury-free excitation and eco-friendly characteristics.
Dipen Kumar Rajak; L. A. Kumaraswamidhas; S. Das
Abstract
Aluminium foam is an isotropic porous metal of cellular structure in the order of 75-80 vol. % of the pores. In turn the novel mechanical, physical and chemical composition, properties depends on the density of foam, i.e. lies in between 0.4-2.4 g/cm 3 . Aluminium foam filled structures are used in collide, ...
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Aluminium foam is an isotropic porous metal of cellular structure in the order of 75-80 vol. % of the pores. In turn the novel mechanical, physical and chemical composition, properties depends on the density of foam, i.e. lies in between 0.4-2.4 g/cm 3 . Aluminium foam filled structures are used in collide, energy absorption, sound absorbing and vibration damping applications. In this article the compressive deformation behaviour of rectangular, square and round aluminium foam (LM 25 + 10wt% SiCp) filled and empty mild steel samples respectively are analyzed to identify the more energy absorption rate per unit volume in diverse strain rate by means of the compressive testing at room temperature. The experiments were performed on a universal testing machine the results showed that the round cross-section had more energy absorption than the rectangular and square cross section respectively. Also the amount of energy absorption will be greater with low foam density for round section tubes. We have seen that an increasing interest in using aluminium foams as inside the thin-wall mild steel tubes for maximum specific energy absorption rate. This work shows the admirable capability of aluminium alloy foam in applications in which it is essential to absorb compression energy.