PROTON IRRADIATION INFLUENCE ON THE MAGNETIC PROPERTIES OF GMR-SVs

Abstract

In this paper, crystal and magnetic properties of proton irradiated giant magnetoresistance spin valves (GMR-SVs) were investigated based on Ta / NiFe / CoFe / Cu / CoFe / IrMn / Ta stack. GMR-SVs were fabricated by magnetron sputtering and irradiated by 5 MeV proton energy. After irradiation, the magnetic phase of GMR-SV core structures was not affected distinctly while the crystal structure of Ta changed with the radiation dose and dose rate. Degradation of the saturated magnetization and the magnetoresistance ratio was shown in the proton-irradiated samples from the magnetization hysteresis curves and the magnetoresistance measurements, which was explained from the change in the zero-field resistance and the exchange interaction.