Effect of Pressure on the Electrical Resistivity of Co/Cu Magnetic Multilayers

In the present work we report the effect of pressure on the temperature dependent electrical resistivity p(T) of three Co/Cu magnetic multilayers (MML) having different Cu layer thickness, t_Cu. Two are antiferromagnetic (AF) and one is ferromagnetic (F). It is found that at room temperature the electrical resistivity, p, of F sample decreases largely by applying pressure compared with that of AF samples; 8 % and 4 % decrease at 2.2 GPa for F and AF samples, respectively. At low temperatures MMLs show a large residual resistivity p₀ reflecting much existence of magnetic and structural disorders in the sample, which decreases largely with increasing pressure having pressure coefficient −2.3 × 10⁻² GPa. Furthermore, the value of the coefficient of a T²-term of p(T), A, is decreased by applying pressure and its decreasing rate, ∂lnA/∂P, of Co/Cu MML with AF state is much larger than that with F state. It is suggested that the s-d interband scattering of conduction electrons due to local spin disorder in Co/Cu MML with AF state is more sensitive to pressure than that in Co/Cu with F state.