Analysis of Fe, Co, Cr concentration in graphite and graphite-Fe composite as high energy milling products using small SS vial with NAA technique

Research about carbon nanotube (CNT) making with technique high energy milling (HEM) as beginning step used stainless steel (SS) vial and SS ball-milling has been done. This process will cause its escape element compiler SS into material sample. The precision of Fe concentration is needed to control because it precursor role in CNT formation. Therefore, analysis for determination the impuritas concentration from SS element such as Fe, Co and Cr into the sample as HEM process effect has been done with Neutron Activation Analysis (NAA) at irradiation facilities of Rabbit System (RS-3) in Reactor GA Siwabessy. Analysis has been done to graphite non-milling and graphite, C-Fe 1% and C_0.2-Fe_0.8 as HEM 100 hours products. The results showed that Fe, Cr, and Co concentration in graphite non-milling were 3119.93±399.48, 30.96±2.78 and 1.10±0.14 μg/g respectively. While concentration analysis results for Fe, Cr and Co in milling process for 100 hours for graphite are 15996.48±1993.59, 189.18±16.51, 7.76±0.30 μg/g, for graphite-Fe 1% (C-Fe 1%) are 16941.01±1922.69, 224.58±20.01, 7.44±0.34 μg/g and for graphite_0.2-Fe_0.8 (C_0.2-Fe_0.8) are 785965.22±55158.49, 395.22±35.80, 0.36±0.06 μg/g. The results showed an significant increase in concentration of Fe in the sample results of milling for 100 hours using a small SS vial. Fe impuritas level is greater than the results of previous studies that use large SS vial. While the results of analysis of the elements Co and Cr due process HEM 100 hours in small or big SS vial do not differ much. From these results suggest the use of different vials provide different impuritas levels. Impuritas Fe content in the sample gives changes in magnetic and electrical properties of materials. (author)