the effect of extract stevia addition on nanocrystalline sic powder prepared by sol gel method using tetraethoxysilane as precursor

silicon carbide (sic) nano powder was synthesized by sol-gel method using teos (tetraethoxysilane) and extract stevia as precursor materials. primary materials were mixed and then stirred with the speed of 250 rpm at 30˚c for 4 hours, the process was done at ph=4.5, prepared solution was kept in an isolated place for 18 hours in order to finish hydrolysis reaction. resultant gels were kept in the extraction fan for 4 hours in 60˚c to dry. in order to investigate carbothermal reduction process, samples were kept in furnace with argon atmospheres at 650, 900, 1400 and 1500˚c for 1.5, 2, 1 and 0.5 hours respectively. to remove remained si and sio₂, pickling by hf was performed. the characterizations of the samples were performed using xrd and sem analysis. the results shown the formation of β-sic with the average grain size of 35 nm and spherical morphology. increasing heating temperature from 900˚c to 1500˚c leads to an increase in the intensity of β-sic peaks and eliminating si and sio₂ contaminations.