Affiliations: Department of Chemistry, Faculty of Sciences and Arts, Khulais, King Abdulaziz University, Saudi Arabia | Refractories, Ceramics and Building Materials Department, National Research Centre, Dokki, Cairo, Egypt | Department of Chemistry, Faculty of Sciences, Sebha University, Libya | Inorganic Chemistry Department, National Research Centre, Dokki, Cairo, Egypt
Note: [] Corresponding author: N.M. Khalil, Department of Chemistry, Faculty of Sciences and Arts, Khulais, King Abdulaziz University, Saudi Arabia. E-mail: [email protected]
Abstract: Different compositions of pure magnesium aluminate spinel, alumina-spinel and magnesia-spinel Nano ceramic materials were prepared using co-precipitation and sol-gel techniques. The powders prepared from different molecular compositions of the starting materials; 1 : 1, 1 : 4 and 4 : 1 of either magnesium nitrate and aluminum nitrate (co-precipitation) or magnesium chloride and aluminum hydroxide (sol-gel) were calcined at different firing temperatures; 900, 1100, 1300 and 1500°C. The solid phase compositions of the calcined samples were investigated using x-ray diffraction analysis (XRD). The crystal size of the fired powders was calculated from XRD patterns using Scherer's equation. The microstructure and solid phase analysis of some selected samples were investigated using scanning electron microscope attached with energy dispersed x-ray unit. Based on the mineralogical, crystal size and microstructure studies, it is concluded that different compositions of pure spinel, magnesia-spinel and alumina-spinel could be attained at different firing temperatures; 900°C, 1100°C, 1300°C and 1500°C via co-precipitation and sol-gel techniques. For economical reasons firing at 900°C is considered sufficient for obtaining pure spinel, magnesia-spinel and alumina-spinel Nano powders (<100 nm); particles prepared via sol-gel are relatively smaller compared with those prepared via co-precipitation.
Keywords: Magnesium aluminate spinel, alumina-spinel and magnesia-spinel, nano ceramic materials, co-precipitation and sol-gel techniques
