Sharif Digital Repository

In this work, we compared formation and properties of heat-treated Ag nanoparticles in silica matrix synthesized by RF- reactive magnetron cosputtering and sol-gel methods separately. The sol-gel and sputtered films were annealed at different temperatures in air and in a reduced environment, respectively. The optical UV-visible Spectrophotometry have shown that the absorption peak appears at 456 and 400 nm wavelength indicating formation of silver nanoparticles in SiO2 matrix for both the sol -gel and sputtering methods at 100 and 800 °C, respectively. XPS measurements showed that the metallic Ag0 nanoparticles can be obtained from both the techniques at these temperatures. According to XPS... 

In this research study, a comparative evaluation of the additional impact of nanometer-sized tetravalent oxides [Zirconia (ZrO2), Titania (TiO2), and Silica (SiO2)] on the properties and performance of Doloma-Magnesia (MgO-CaO) ceramic refractories, with an emphasis on their hydration resistance improvement, has been done. For this purpose, from 0 to 2.5 wt% ZrO2, TiO2, and SiO2 nanometer-sized particles have been added to the Doloma-Magnesia compositions. After formulation and mixing of the starting materials, the pressed samples (at 150 MPa) were tempered (at 250 °C for 12 h) and fired in a shuttle furnace (at 1650 °C for 3 h). The physical, mechanical, and thermo-mechanical properties of...