Improvement of giant magnetoresistance performance of a metal layered structure

A metal layered structure consisting of Cr/Cu buffer layer and two Co layer s with different thickness, separated by a Cu spacer, was deposited on Si w afers using magnetron sputtering. The influence of the individual layer's t hickness on the magneto transport and magnetic hysteresis was studied. Opti mization of the magnetoresistance performance was supported by the current in-plane giant magnetoresistance (GMR) modeling based on the solution to th e Boltzmann transport equation. The best structures demonstrated very sharp magnetization reversal of the lower Co layer at about 100 Oe accompanied b y resistivity change with a rate of 0.9%/Oe. Maximum GMR effect measured at 5 K was 9.6%. Samples with capping layers exhibited substantially smaller switching fields of the upper Co layer than the uncapped samples with a min ute amount of CoO. (C) 2000 American Institute of Physics. [S0021-8979(00)6 2608-7].