Parametric sensitivity analysis on the giant magnetoresistive characteristics of synthetic antiferromagnet-based spin-valves

Abstract A series of static calculations based on the Landau–Lifschitz–Gilbert equation incorporating a single-domain multilayer model applied on synthetic antiferrimagnet (SyAF) based spin-valve structures was carried out to investigate their giant magnetoresistive (GMR) transfer behaviors. The typical multilayer structure comprises NiFe (3.2)/CoFe (1.6)/Cu (2.8)/CoFe (P2, 3.0)/Ru (0.7)/CoFe (P1, 1.5)/IrMn (9.0) (in nm). Four fitting parameters were obtained from the comparisons between the calculated and experimental results: (i) the indirect exchange coupling energy ( J 1 ) between P1 and P2 layers=−1.5 erg/cm 2 , (ii) the exchange biasing energy between P1 and IrMn layer ( J eb )=0.13 erg/cm 2 , (iii) the relative GMR contribution ( R ) due to the angular difference of magnetizations in CoFe (P2)/Ru/CoFe (P1) trilayers=3%, and (iv) the induced uniaxial anisotropy value ( H ua ) of CoFe layers=40 Oe. These values appear reasonable and are within the range of those reported in the literatures, indicating that the present single-domain model works well. In order to examine how these parameters affect the MR transfer curve, one of these parameters was systematically varied while the rest were fixed. J 1 was found to be mainly related with the saturation field ( H s ) and the field at which the maximum sub-peak MR ratio ( H sub ). J eb influenced on the effective exchange field ( H ex.eff ). It was also observed that R increases the total MR ratio, but the MR transfer curve was less affected by H ua .