Magnetoresistance properties of Fe_0,2C_0,8 composite materials pre and post gamma irradiated at 250 kGy dose

Research about change of, magnetoresistance properties of Fe_0,2C_0,8 composite materials pre and post gamma irradiation at a dose of 250 kGy was carried out. Fe_0,2C_0,8 was prepared by mixing of Fe and C powder with the ratio of Fe : C set on 20:80 in weight %. In this research, the phase structure and magnetic properties of Fe_0,2C_0,8 composite materials after 250 KGy dose of gamma irradiation have been measured and analyzed. The phase structure of Fe_0,2C_0,8 was analyzed using X-ray diffractometer (XRD), whole the magnetoresistance properties was characterized using Four Point Probe method. The analyzing results showed the decreasing of X-ray diffraction peak intensity, but also in the same time showed the increasing of magnetoresistance properties after gamma irradiation. The enhancement of magnetoresistance value reached 5 times at 7,5 kOe magnetic field. This enhancement was caused due to structure defect within Fe_0,2C_0,8 composite initiated by interaction between radiation of gamma ray and composite materials that further causes a change of magnetic interaction intensity in this materials. (author)