Effect of Co Ion Implantation on GMR of [NiFeCo(10 nm)/Ag(10 nm)]×20 Multilayer Film

The composition, phase structure and microstructure of the discontinuous multilayer film NiFeCo(10 nm)/ Ag(10 nm)]×20 were investigated after Co ion implantation and annealing at 280, 320, 360 and 400℃, respectively. GMR (giant magnetoresistance) ratio of the film with/without Co ion implantation was measured. The results showed that Co ion implantation decreased the granule size of the annealed multilayer film, and increased Hc value and GMR ratio of the multilayer film. After annealing at 360℃, the multilayer film NiFeCo(10 nm)/Ag(10 nm)]×20 with/without Co ion implantation both exhibited the highest GMR ratio of 12.4%/11% under 79.6 kA/m of applied saturation magnetic field.