The spectroscopic properties of lithium borate glasses as a function of Nd3＋ ions concentration were reported.Optical absorption spectra of these glasses showed a number of absorption bands in ultra violet and visibl...The spectroscopic properties of lithium borate glasses as a function of Nd3＋ ions concentration were reported.Optical absorption spectra of these glasses showed a number of absorption bands in ultra violet and visible region.Optical absorption edge was found to shift towards the longer wavelength（red shift） with increase in Nd2O3.Luminescence spectra revealed three major bands at 902, 1063 and 1334 nm which was due to 4F3/2→4I9/2, 11/2 ＆13/2 transitions of Nd3＋ ions.Luminescence intensity was maximum for 1 mol.% Nd2O3 and further increase in Nd2O3 resulted in luminescence quenching.The luminescence quenching behavior at higher concentration of Nd2O3 was attributed to the Nd3＋-Nd3＋ interaction in the glass matrix.An absorption and emission property of these glasses suggested that these glasses could be useful for 1.06 μm infrared laser applications.展开更多
Nano-sized calcium silicate powders were synthesized at room temperature by the new mechanochemical method using a high energy planetary ball mill. The formation of calcium silicate from its raw materials (calcium car...Nano-sized calcium silicate powders were synthesized at room temperature by the new mechanochemical method using a high energy planetary ball mill. The formation of calcium silicate from its raw materials (calcium carbonate and dehydrated silica gel) was monitored by the XRD analysis with progression of ball milling. It is observed that the synthetic process comes to an end through the following three sequential stages: comminution of raw materials, recombination of comminuted raw materials to final product, and comminution of final product to smaller sizes. The nanostructure of the synthesized powder was realized by the FESEM photomicrograph, TEM image and XRD analyses. These analytical observations have revealed that the nano-sized polycrystalline calcium silicate particles are formed after about 6 h of ball milling and they are spheroidal in shape. The average particle size of the as-generated calcium silicate nanocrystalline powders is found to be around 21 nm which decreases with increasing ball milling but increases with annealing at elevated temperature.展开更多
文摘The spectroscopic properties of lithium borate glasses as a function of Nd3＋ ions concentration were reported.Optical absorption spectra of these glasses showed a number of absorption bands in ultra violet and visible region.Optical absorption edge was found to shift towards the longer wavelength（red shift） with increase in Nd2O3.Luminescence spectra revealed three major bands at 902, 1063 and 1334 nm which was due to 4F3/2→4I9/2, 11/2 ＆13/2 transitions of Nd3＋ ions.Luminescence intensity was maximum for 1 mol.% Nd2O3 and further increase in Nd2O3 resulted in luminescence quenching.The luminescence quenching behavior at higher concentration of Nd2O3 was attributed to the Nd3＋-Nd3＋ interaction in the glass matrix.An absorption and emission property of these glasses suggested that these glasses could be useful for 1.06 μm infrared laser applications.
文摘Nano-sized calcium silicate powders were synthesized at room temperature by the new mechanochemical method using a high energy planetary ball mill. The formation of calcium silicate from its raw materials (calcium carbonate and dehydrated silica gel) was monitored by the XRD analysis with progression of ball milling. It is observed that the synthetic process comes to an end through the following three sequential stages: comminution of raw materials, recombination of comminuted raw materials to final product, and comminution of final product to smaller sizes. The nanostructure of the synthesized powder was realized by the FESEM photomicrograph, TEM image and XRD analyses. These analytical observations have revealed that the nano-sized polycrystalline calcium silicate particles are formed after about 6 h of ball milling and they are spheroidal in shape. The average particle size of the as-generated calcium silicate nanocrystalline powders is found to be around 21 nm which decreases with increasing ball milling but increases with annealing at elevated temperature.
